//===-- CommandInterpreter.cpp ----------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include <string>
#include <vector>
#include <stdlib.h>

#include "CommandObjectScript.h"
#include "lldb/Interpreter/CommandObjectRegexCommand.h"

#include "../Commands/CommandObjectApropos.h"
#include "../Commands/CommandObjectArgs.h"
#include "../Commands/CommandObjectBreakpoint.h"
#include "../Commands/CommandObjectBugreport.h"
#include "../Commands/CommandObjectDisassemble.h"
#include "../Commands/CommandObjectExpression.h"
#include "../Commands/CommandObjectFrame.h"
#include "../Commands/CommandObjectGUI.h"
#include "../Commands/CommandObjectHelp.h"
#include "../Commands/CommandObjectLog.h"
#include "../Commands/CommandObjectMemory.h"
#include "../Commands/CommandObjectPlatform.h"
#include "../Commands/CommandObjectPlugin.h"
#include "../Commands/CommandObjectProcess.h"
#include "../Commands/CommandObjectQuit.h"
#include "../Commands/CommandObjectRegister.h"
#include "../Commands/CommandObjectSettings.h"
#include "../Commands/CommandObjectSource.h"
#include "../Commands/CommandObjectCommands.h"
#include "../Commands/CommandObjectSyntax.h"
#include "../Commands/CommandObjectTarget.h"
#include "../Commands/CommandObjectThread.h"
#include "../Commands/CommandObjectType.h"
#include "../Commands/CommandObjectVersion.h"
#include "../Commands/CommandObjectWatchpoint.h"
#include "../Commands/CommandObjectLanguage.h"

#include "lldb/Core/Debugger.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Core/State.h"
#include "lldb/Core/Stream.h"
#include "lldb/Core/StreamFile.h"
#include "lldb/Core/Timer.h"

#ifndef LLDB_DISABLE_LIBEDIT
#include "lldb/Host/Editline.h"
#endif
#include "lldb/Host/Host.h"
#include "lldb/Host/HostInfo.h"

#include "lldb/Interpreter/Args.h"
#include "lldb/Interpreter/CommandCompletions.h"
#include "lldb/Interpreter/CommandInterpreter.h"
#include "lldb/Interpreter/CommandReturnObject.h"
#include "lldb/Interpreter/Options.h"
#include "lldb/Interpreter/OptionValueProperties.h"
#include "lldb/Interpreter/Property.h"


#include "lldb/Target/Process.h"
#include "lldb/Target/Thread.h"
#include "lldb/Target/TargetList.h"

#include "lldb/Utility/CleanUp.h"

#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Path.h"

using namespace lldb;
using namespace lldb_private;

static const char *k_white_space = " \t\v";

static PropertyDefinition
g_properties[] =
{
    { "expand-regex-aliases", OptionValue::eTypeBoolean, true, false, nullptr, nullptr, "If true, regular expression alias commands will show the expanded command that will be executed. This can be used to debug new regular expression alias commands." },
    { "prompt-on-quit", OptionValue::eTypeBoolean, true, true, nullptr, nullptr, "If true, LLDB will prompt you before quitting if there are any live processes being debugged. If false, LLDB will quit without asking in any case." },
    { "stop-command-source-on-error", OptionValue::eTypeBoolean, true, true, nullptr, nullptr, "If true, LLDB will stop running a 'command source' script upon encountering an error." },
    { "space-repl-prompts", OptionValue::eTypeBoolean, true, false, nullptr, nullptr, "If true, blank lines will be printed between between REPL submissions." },
    { nullptr                  , OptionValue::eTypeInvalid, true, 0    , nullptr, nullptr, nullptr }
};

enum
{
    ePropertyExpandRegexAliases = 0,
    ePropertyPromptOnQuit = 1,
    ePropertyStopCmdSourceOnError = 2,
    eSpaceReplPrompts = 3
};

ConstString &
CommandInterpreter::GetStaticBroadcasterClass ()
{
    static ConstString class_name ("lldb.commandInterpreter");
    return class_name;
}

CommandInterpreter::CommandInterpreter(Debugger &debugger, ScriptLanguage script_language, bool synchronous_execution)
    : Broadcaster(debugger.GetBroadcasterManager(), CommandInterpreter::GetStaticBroadcasterClass().AsCString()),
      Properties(OptionValuePropertiesSP(new OptionValueProperties(ConstString("interpreter")))),
      IOHandlerDelegate(IOHandlerDelegate::Completion::LLDBCommand),
      m_debugger(debugger),
      m_synchronous_execution(synchronous_execution),
      m_skip_lldbinit_files(false),
      m_skip_app_init_files(false),
      m_script_interpreter_sp(),
      m_command_io_handler_sp(),
      m_comment_char('#'),
      m_batch_command_mode(false),
      m_truncation_warning(eNoTruncation),
      m_command_source_depth(0),
      m_num_errors(0),
      m_quit_requested(false),
      m_stopped_for_crash(false)
{
    debugger.SetScriptLanguage (script_language);
    SetEventName (eBroadcastBitThreadShouldExit, "thread-should-exit");
    SetEventName (eBroadcastBitResetPrompt, "reset-prompt");
    SetEventName (eBroadcastBitQuitCommandReceived, "quit");    
    CheckInWithManager ();
    m_collection_sp->Initialize (g_properties);
}

bool
CommandInterpreter::GetExpandRegexAliases () const
{
    const uint32_t idx = ePropertyExpandRegexAliases;
    return m_collection_sp->GetPropertyAtIndexAsBoolean (nullptr, idx, g_properties[idx].default_uint_value != 0);
}

bool
CommandInterpreter::GetPromptOnQuit () const
{
    const uint32_t idx = ePropertyPromptOnQuit;
    return m_collection_sp->GetPropertyAtIndexAsBoolean (nullptr, idx, g_properties[idx].default_uint_value != 0);
}

void
CommandInterpreter::SetPromptOnQuit (bool enable)
{
    const uint32_t idx = ePropertyPromptOnQuit;
    m_collection_sp->SetPropertyAtIndexAsBoolean (nullptr, idx, enable);
}

void
CommandInterpreter::ResolveCommand(const char *command_line, CommandReturnObject &result)
{
    std::string command = command_line;
    if (ResolveCommandImpl(command, result) != nullptr) {
        result.AppendMessageWithFormat("%s", command.c_str());
        result.SetStatus(eReturnStatusSuccessFinishResult);
    }
}


bool
CommandInterpreter::GetStopCmdSourceOnError () const
{
    const uint32_t idx = ePropertyStopCmdSourceOnError;
    return m_collection_sp->GetPropertyAtIndexAsBoolean (nullptr, idx, g_properties[idx].default_uint_value != 0);
}

bool
CommandInterpreter::GetSpaceReplPrompts () const
{
    const uint32_t idx = eSpaceReplPrompts;
    return m_collection_sp->GetPropertyAtIndexAsBoolean (nullptr, idx, g_properties[idx].default_uint_value != 0);
}

void
CommandInterpreter::Initialize ()
{
    Timer scoped_timer (__PRETTY_FUNCTION__, __PRETTY_FUNCTION__);

    CommandReturnObject result;

    LoadCommandDictionary ();

    // An alias arguments vector to reuse - reset it before use...
    OptionArgVectorSP alias_arguments_vector_sp (new OptionArgVector);
    
    // Set up some initial aliases.
    CommandObjectSP cmd_obj_sp = GetCommandSPExact ("quit", false);
    if (cmd_obj_sp)
    {
        AddAlias ("q", cmd_obj_sp);
        AddAlias ("exit", cmd_obj_sp);
    }
    
    cmd_obj_sp = GetCommandSPExact ("_regexp-attach",false);
    if (cmd_obj_sp)
        AddAlias ("attach", cmd_obj_sp)->SetSyntax(cmd_obj_sp->GetSyntax());

    cmd_obj_sp = GetCommandSPExact ("process detach",false);
    if (cmd_obj_sp)
    {
        AddAlias ("detach", cmd_obj_sp);
    }

    cmd_obj_sp = GetCommandSPExact ("process continue", false);
    if (cmd_obj_sp)
    {
        AddAlias ("c", cmd_obj_sp);
        AddAlias ("continue", cmd_obj_sp);
    }

    cmd_obj_sp = GetCommandSPExact ("_regexp-break",false);
    if (cmd_obj_sp)
        AddAlias ("b", cmd_obj_sp)->SetSyntax(cmd_obj_sp->GetSyntax());

    cmd_obj_sp = GetCommandSPExact ("_regexp-tbreak",false);
    if (cmd_obj_sp)
        AddAlias ("tbreak", cmd_obj_sp)->SetSyntax(cmd_obj_sp->GetSyntax());

    cmd_obj_sp = GetCommandSPExact ("thread step-inst", false);
    if (cmd_obj_sp)
    {
        AddAlias ("stepi", cmd_obj_sp);
        AddAlias ("si", cmd_obj_sp);
    }

    cmd_obj_sp = GetCommandSPExact ("thread step-inst-over", false);
    if (cmd_obj_sp)
    {
        AddAlias ("nexti", cmd_obj_sp);
        AddAlias ("ni", cmd_obj_sp);
    }

    cmd_obj_sp = GetCommandSPExact ("thread step-in", false);
    if (cmd_obj_sp)
    {
        AddAlias ("s", cmd_obj_sp);
        AddAlias ("step", cmd_obj_sp);
        CommandAlias *sif_alias = AddAlias ("sif", cmd_obj_sp, "--end-linenumber block --step-in-target %1");
        if (sif_alias)
        {
            sif_alias->SetHelp("Step through the current block, stopping if you step "
                               "directly into a function whose name matches the TargetFunctionName.");
            sif_alias->SetSyntax("sif <TargetFunctionName>");
        }
    }

    cmd_obj_sp = GetCommandSPExact ("thread step-over", false);
    if (cmd_obj_sp)
    {
        AddAlias ("n", cmd_obj_sp);
        AddAlias ("next", cmd_obj_sp);
    }

    cmd_obj_sp = GetCommandSPExact ("thread step-out", false);
    if (cmd_obj_sp)
    {
        AddAlias ("finish", cmd_obj_sp);
    }

    cmd_obj_sp = GetCommandSPExact ("frame select", false);
    if (cmd_obj_sp)
    {
        AddAlias ("f", cmd_obj_sp);
    }

    cmd_obj_sp = GetCommandSPExact ("thread select", false);
    if (cmd_obj_sp)
    {
        AddAlias ("t", cmd_obj_sp);
    }

    cmd_obj_sp = GetCommandSPExact ("_regexp-jump",false);
    if (cmd_obj_sp)
    {
        AddAlias ("j", cmd_obj_sp)->SetSyntax(cmd_obj_sp->GetSyntax());
        AddAlias ("jump", cmd_obj_sp)->SetSyntax(cmd_obj_sp->GetSyntax());
    }

    cmd_obj_sp = GetCommandSPExact ("_regexp-list", false);
    if (cmd_obj_sp)
    {
        AddAlias ("l", cmd_obj_sp)->SetSyntax(cmd_obj_sp->GetSyntax());
        AddAlias ("list", cmd_obj_sp)->SetSyntax(cmd_obj_sp->GetSyntax());
    }

    cmd_obj_sp = GetCommandSPExact ("_regexp-env", false);
    if (cmd_obj_sp)
        AddAlias ("env", cmd_obj_sp)->SetSyntax(cmd_obj_sp->GetSyntax());

    cmd_obj_sp = GetCommandSPExact ("memory read", false);
    if (cmd_obj_sp)
        AddAlias ("x", cmd_obj_sp);

    cmd_obj_sp = GetCommandSPExact ("_regexp-up", false);
    if (cmd_obj_sp)
        AddAlias ("up", cmd_obj_sp)->SetSyntax(cmd_obj_sp->GetSyntax());

    cmd_obj_sp = GetCommandSPExact ("_regexp-down", false);
    if (cmd_obj_sp)
        AddAlias ("down", cmd_obj_sp)->SetSyntax(cmd_obj_sp->GetSyntax());

    cmd_obj_sp = GetCommandSPExact ("_regexp-display", false);
    if (cmd_obj_sp)
        AddAlias ("display", cmd_obj_sp)->SetSyntax(cmd_obj_sp->GetSyntax());
        
    cmd_obj_sp = GetCommandSPExact ("disassemble", false);
    if (cmd_obj_sp)
        AddAlias ("dis", cmd_obj_sp);

    cmd_obj_sp = GetCommandSPExact ("disassemble", false);
    if (cmd_obj_sp)
        AddAlias ("di", cmd_obj_sp);



    cmd_obj_sp = GetCommandSPExact ("_regexp-undisplay", false);
    if (cmd_obj_sp)
        AddAlias ("undisplay", cmd_obj_sp)->SetSyntax(cmd_obj_sp->GetSyntax());

    cmd_obj_sp = GetCommandSPExact ("_regexp-bt", false);
    if (cmd_obj_sp)
        AddAlias ("bt", cmd_obj_sp)->SetSyntax(cmd_obj_sp->GetSyntax());

    cmd_obj_sp = GetCommandSPExact ("target create", false);
    if (cmd_obj_sp)
        AddAlias ("file", cmd_obj_sp);

    cmd_obj_sp = GetCommandSPExact ("target modules", false);
    if (cmd_obj_sp)
        AddAlias ("image", cmd_obj_sp);


    alias_arguments_vector_sp.reset(new OptionArgVector);

    cmd_obj_sp = GetCommandSPExact ("expression", false);
    if (cmd_obj_sp)
    {        
        AddAlias ("p", cmd_obj_sp, "--")->SetHelpLong("");
        AddAlias ("print", cmd_obj_sp, "--")->SetHelpLong("");
        AddAlias ("call", cmd_obj_sp, "--")->SetHelpLong("");

        if (auto po = AddAlias ("po", cmd_obj_sp, "-O --"))
        {
            po->SetHelp("Evaluate an expression in the current program context, using user defined variables and variables currently in scope, and display the result of evaluation in a language-specific manner.");
            po->SetHelpLong("");
        }

        AddAlias ("repl", cmd_obj_sp, "--repl --");

        AddAlias("parray", cmd_obj_sp, "--element-count %1 --")->SetHelpLong("");
        AddAlias("poarray", cmd_obj_sp, "--object-description --element-count %1 --")->SetHelpLong("");
    }
    
    cmd_obj_sp = GetCommandSPExact ("process kill", false);
    if (cmd_obj_sp)
    {
        AddAlias ("kill", cmd_obj_sp);
    }
    
    cmd_obj_sp = GetCommandSPExact ("process launch", false);
    if (cmd_obj_sp)
    {
        alias_arguments_vector_sp.reset (new OptionArgVector);
#if defined (__arm__) || defined (__arm64__) || defined (__aarch64__)
        AddAlias ("r", cmd_obj_sp, "--");
        AddAlias ("run", cmd_obj_sp, "--");
#else
    #if defined(__APPLE__)
        std::string shell_option;
        shell_option.append("--shell-expand-args");
        shell_option.append(" true");
        shell_option.append(" --");
        AddAlias ("r", cmd_obj_sp, "--shell-expand-args true --");
        AddAlias ("run", cmd_obj_sp, "--shell-expand-args true --");
    #else
        StreamString defaultshell;
        defaultshell.Printf("--shell=%s --", HostInfo::GetDefaultShell().GetPath().c_str());
        AddAlias ("r", cmd_obj_sp, defaultshell.GetData());
        AddAlias ("run", cmd_obj_sp, defaultshell.GetData());
    #endif
#endif
    }
    
    cmd_obj_sp = GetCommandSPExact ("target symbols add", false);
    if (cmd_obj_sp)
    {
        AddAlias ("add-dsym", cmd_obj_sp);
    }
    
    cmd_obj_sp = GetCommandSPExact ("breakpoint set", false);
    if (cmd_obj_sp)
    {
        AddAlias ("rbreak", cmd_obj_sp, "--func-regex %1");
    }
}

void
CommandInterpreter::Clear()
{
    m_command_io_handler_sp.reset();

    if (m_script_interpreter_sp)
        m_script_interpreter_sp->Clear();
}

const char *
CommandInterpreter::ProcessEmbeddedScriptCommands (const char *arg)
{
    // This function has not yet been implemented.

    // Look for any embedded script command
    // If found,
    //    get interpreter object from the command dictionary,
    //    call execute_one_command on it,
    //    get the results as a string,
    //    substitute that string for current stuff.

    return arg;
}


void
CommandInterpreter::LoadCommandDictionary ()
{
    Timer scoped_timer (__PRETTY_FUNCTION__, __PRETTY_FUNCTION__);

    lldb::ScriptLanguage script_language = m_debugger.GetScriptLanguage();
    
    m_command_dict["apropos"]   = CommandObjectSP (new CommandObjectApropos (*this));
    m_command_dict["breakpoint"]= CommandObjectSP (new CommandObjectMultiwordBreakpoint (*this));
    m_command_dict["bugreport"] = CommandObjectSP (new CommandObjectMultiwordBugreport (*this));
    m_command_dict["command"]   = CommandObjectSP (new CommandObjectMultiwordCommands (*this));
    m_command_dict["disassemble"] = CommandObjectSP (new CommandObjectDisassemble (*this));
    m_command_dict["expression"]= CommandObjectSP (new CommandObjectExpression (*this));
    m_command_dict["frame"]     = CommandObjectSP (new CommandObjectMultiwordFrame (*this));
    m_command_dict["gui"]       = CommandObjectSP (new CommandObjectGUI (*this));
    m_command_dict["help"]      = CommandObjectSP (new CommandObjectHelp (*this));
    m_command_dict["log"]       = CommandObjectSP (new CommandObjectLog (*this));
    m_command_dict["memory"]    = CommandObjectSP (new CommandObjectMemory (*this));
    m_command_dict["platform"]  = CommandObjectSP (new CommandObjectPlatform (*this));
    m_command_dict["plugin"]    = CommandObjectSP (new CommandObjectPlugin (*this));
    m_command_dict["process"]   = CommandObjectSP (new CommandObjectMultiwordProcess (*this));
    m_command_dict["quit"]      = CommandObjectSP (new CommandObjectQuit (*this));
    m_command_dict["register"]  = CommandObjectSP (new CommandObjectRegister (*this));
    m_command_dict["script"]    = CommandObjectSP (new CommandObjectScript (*this, script_language));
    m_command_dict["settings"]  = CommandObjectSP (new CommandObjectMultiwordSettings (*this));
    m_command_dict["source"]    = CommandObjectSP (new CommandObjectMultiwordSource (*this));
    m_command_dict["target"]    = CommandObjectSP (new CommandObjectMultiwordTarget (*this));
    m_command_dict["thread"]    = CommandObjectSP (new CommandObjectMultiwordThread (*this));
    m_command_dict["type"]      = CommandObjectSP (new CommandObjectType (*this));
    m_command_dict["version"]   = CommandObjectSP (new CommandObjectVersion (*this));
    m_command_dict["watchpoint"]= CommandObjectSP (new CommandObjectMultiwordWatchpoint (*this));
    m_command_dict["language"]  = CommandObjectSP (new CommandObjectLanguage(*this));

    const char *break_regexes[][2] = {{"^(.*[^[:space:]])[[:space:]]*:[[:space:]]*([[:digit:]]+)[[:space:]]*$", "breakpoint set --file '%1' --line %2"},
                                      {"^/([^/]+)/$", "breakpoint set --source-pattern-regexp '%1'"},
                                      {"^([[:digit:]]+)[[:space:]]*$", "breakpoint set --line %1"},
                                      {"^\\*?(0x[[:xdigit:]]+)[[:space:]]*$", "breakpoint set --address %1"},
                                      {"^[\"']?([-+]?\\[.*\\])[\"']?[[:space:]]*$", "breakpoint set --name '%1'"},
                                      {"^(-.*)$", "breakpoint set %1"},
                                      {"^(.*[^[:space:]])`(.*[^[:space:]])[[:space:]]*$", "breakpoint set --name '%2' --shlib '%1'"},
                                      {"^\\&(.*[^[:space:]])[[:space:]]*$", "breakpoint set --name '%1' --skip-prologue=0"},
                                      {"^[\"']?(.*[^[:space:]\"'])[\"']?[[:space:]]*$", "breakpoint set --name '%1'"}};
    
    size_t num_regexes = llvm::array_lengthof(break_regexes);
        
    std::unique_ptr<CommandObjectRegexCommand>
    break_regex_cmd_ap(new CommandObjectRegexCommand (*this,
                                                      "_regexp-break",
                                                      "Set a breakpoint using a regular expression to specify the location, where <linenum> is in decimal and <address> is in hex.\n",
                                                      "\n_regexp-break <filename>:<linenum> # _regexp-break main.c:12      // Break on line 12 of main.c\n"
                                                      "_regexp-break <linenum>            # _regexp-break 12             // Break on line 12 of current file\n"
                                                      "_regexp-break <address>            # _regexp-break 0x1234000      // Break on address 0x1234000\n"
                                                      "_regexp-break <name>               # _regexp-break main           // Break in 'main' after the prologue\n"
                                                      "_regexp-break &<name>              # _regexp-break &main          // Break on the first instruction in 'main'\n"
                                                      "_regexp-break <module>`<name>      # _regexp-break libc.so`malloc // Break in 'malloc' only in the 'libc.so' shared library\n"
                                                      "_regexp-break /<source-regex>/     # _regexp-break /break here/   // Break on all lines that match the regular expression 'break here' in the current file.\n",
                                                      2,
                                                      CommandCompletions::eSymbolCompletion |
                                                      CommandCompletions::eSourceFileCompletion,
                                                      false));

    if (break_regex_cmd_ap.get())
    {
        bool success = true;
        for (size_t i = 0; i < num_regexes; i++)
        {
            success = break_regex_cmd_ap->AddRegexCommand (break_regexes[i][0], break_regexes[i][1]);
            if (!success)
                break;
        }
        success = break_regex_cmd_ap->AddRegexCommand("^$", "breakpoint list --full");

        if (success)
        {
            CommandObjectSP break_regex_cmd_sp(break_regex_cmd_ap.release());
            m_command_dict[break_regex_cmd_sp->GetCommandName ()] = break_regex_cmd_sp;
        }
    }

    std::unique_ptr<CommandObjectRegexCommand>
    tbreak_regex_cmd_ap(new CommandObjectRegexCommand (*this,
                                                      "_regexp-tbreak",
                                                      "Set a one shot breakpoint using a regular expression to specify the location, where <linenum> is in decimal and <address> is in hex.",
                                                      "_regexp-tbreak [<filename>:<linenum>]\n_regexp-break [<linenum>]\n_regexp-break [<address>]\n_regexp-break <...>",
                                                       2,
                                                       CommandCompletions::eSymbolCompletion |
                                                       CommandCompletions::eSourceFileCompletion,
                                                       false));

    if (tbreak_regex_cmd_ap.get())
    {
        bool success = true;
        for (size_t i = 0; i < num_regexes; i++)
        {
            // If you add a resultant command string longer than 1024 characters be sure to increase the size of this buffer.
            char buffer[1024];
            int num_printed = snprintf(buffer, 1024, "%s %s", break_regexes[i][1], "-o");
            assert (num_printed < 1024);
            UNUSED_IF_ASSERT_DISABLED(num_printed);
            success = tbreak_regex_cmd_ap->AddRegexCommand (break_regexes[i][0], buffer);
            if (!success)
                break;
        }
        success = tbreak_regex_cmd_ap->AddRegexCommand("^$", "breakpoint list --full");

        if (success)
        {
            CommandObjectSP tbreak_regex_cmd_sp(tbreak_regex_cmd_ap.release());
            m_command_dict[tbreak_regex_cmd_sp->GetCommandName ()] = tbreak_regex_cmd_sp;
        }
    }

    std::unique_ptr<CommandObjectRegexCommand>
    attach_regex_cmd_ap(new CommandObjectRegexCommand (*this,
                                                       "_regexp-attach",
                                                       "Attach to a process id if in decimal, otherwise treat the argument as a process name to attach to.",
                                                       "_regexp-attach [<pid>]\n_regexp-attach [<process-name>]",
                                                       2,
                                                       0,
                                                       false));
    if (attach_regex_cmd_ap.get())
    {
        if (attach_regex_cmd_ap->AddRegexCommand("^([0-9]+)[[:space:]]*$", "process attach --pid %1") &&
            attach_regex_cmd_ap->AddRegexCommand("^(-.*|.* -.*)$", "process attach %1") && // Any options that are specified get passed to 'process attach'
            attach_regex_cmd_ap->AddRegexCommand("^(.+)$", "process attach --name '%1'") &&
            attach_regex_cmd_ap->AddRegexCommand("^$", "process attach"))
        {
            CommandObjectSP attach_regex_cmd_sp(attach_regex_cmd_ap.release());
            m_command_dict[attach_regex_cmd_sp->GetCommandName ()] = attach_regex_cmd_sp;
        }
    }
    
    std::unique_ptr<CommandObjectRegexCommand>
    down_regex_cmd_ap(new CommandObjectRegexCommand (*this,
                                                     "_regexp-down",
                                                     "Go down \"n\" frames in the stack (1 frame by default).",
                                                     "_regexp-down [n]",
                                                     2,
                                                     0,
                                                     false));
    if (down_regex_cmd_ap.get())
    {
        if (down_regex_cmd_ap->AddRegexCommand("^$", "frame select -r -1") &&
            down_regex_cmd_ap->AddRegexCommand("^([0-9]+)$", "frame select -r -%1"))
        {
            CommandObjectSP down_regex_cmd_sp(down_regex_cmd_ap.release());
            m_command_dict[down_regex_cmd_sp->GetCommandName ()] = down_regex_cmd_sp;
        }
    }
    
    std::unique_ptr<CommandObjectRegexCommand>
    up_regex_cmd_ap(new CommandObjectRegexCommand (*this,
                                                   "_regexp-up",
                                                   "Go up \"n\" frames in the stack (1 frame by default).",
                                                   "_regexp-up [n]",
                                                   2,
                                                   0,
                                                   false));
    if (up_regex_cmd_ap.get())
    {
        if (up_regex_cmd_ap->AddRegexCommand("^$", "frame select -r 1") &&
            up_regex_cmd_ap->AddRegexCommand("^([0-9]+)$", "frame select -r %1"))
        {
            CommandObjectSP up_regex_cmd_sp(up_regex_cmd_ap.release());
            m_command_dict[up_regex_cmd_sp->GetCommandName ()] = up_regex_cmd_sp;
        }
    }

    std::unique_ptr<CommandObjectRegexCommand>
    display_regex_cmd_ap(new CommandObjectRegexCommand (*this,
                                                        "_regexp-display",
                                                        "Add an expression evaluation stop-hook.",
                                                        "_regexp-display expression",
                                                        2,
                                                        0,
                                                        false));
    if (display_regex_cmd_ap.get())
    {
        if (display_regex_cmd_ap->AddRegexCommand("^(.+)$", "target stop-hook add -o \"expr -- %1\""))
        {
            CommandObjectSP display_regex_cmd_sp(display_regex_cmd_ap.release());
            m_command_dict[display_regex_cmd_sp->GetCommandName ()] = display_regex_cmd_sp;
        }
    }

    std::unique_ptr<CommandObjectRegexCommand>
    undisplay_regex_cmd_ap(new CommandObjectRegexCommand (*this,
                                                          "_regexp-undisplay",
                                                          "Remove an expression evaluation stop-hook.",
                                                          "_regexp-undisplay stop-hook-number",
                                                          2,
                                                          0,
                                                          false));
    if (undisplay_regex_cmd_ap.get())
    {
        if (undisplay_regex_cmd_ap->AddRegexCommand("^([0-9]+)$", "target stop-hook delete %1"))
        {
            CommandObjectSP undisplay_regex_cmd_sp(undisplay_regex_cmd_ap.release());
            m_command_dict[undisplay_regex_cmd_sp->GetCommandName ()] = undisplay_regex_cmd_sp;
        }
    }

    std::unique_ptr<CommandObjectRegexCommand>
    connect_gdb_remote_cmd_ap(new CommandObjectRegexCommand (*this,
                                                             "gdb-remote",
                                                             "Connect to a remote GDB server.  If no hostname is provided, localhost is assumed.",
                                                             "gdb-remote [<hostname>:]<portnum>",
                                                             2,
                                                             0,
                                                             false));
    if (connect_gdb_remote_cmd_ap.get())
    {
        if (connect_gdb_remote_cmd_ap->AddRegexCommand("^([^:]+:[[:digit:]]+)$", "process connect --plugin gdb-remote connect://%1") &&
            connect_gdb_remote_cmd_ap->AddRegexCommand("^([[:digit:]]+)$", "process connect --plugin gdb-remote connect://localhost:%1"))
        {
            CommandObjectSP command_sp(connect_gdb_remote_cmd_ap.release());
            m_command_dict[command_sp->GetCommandName ()] = command_sp;
        }
    }

    std::unique_ptr<CommandObjectRegexCommand>
    connect_kdp_remote_cmd_ap(new CommandObjectRegexCommand (*this,
                                                             "kdp-remote",
                                                             "Connect to a remote KDP server.  udp port 41139 is the default port number.",
                                                             "kdp-remote <hostname>[:<portnum>]",
                                                             2,
                                                             0,
                                                             false));
    if (connect_kdp_remote_cmd_ap.get())
    {
        if (connect_kdp_remote_cmd_ap->AddRegexCommand("^([^:]+:[[:digit:]]+)$", "process connect --plugin kdp-remote udp://%1") &&
            connect_kdp_remote_cmd_ap->AddRegexCommand("^(.+)$", "process connect --plugin kdp-remote udp://%1:41139"))
        {
            CommandObjectSP command_sp(connect_kdp_remote_cmd_ap.release());
            m_command_dict[command_sp->GetCommandName ()] = command_sp;
        }
    }

    std::unique_ptr<CommandObjectRegexCommand>
    bt_regex_cmd_ap(new CommandObjectRegexCommand (*this,
                                                   "_regexp-bt",
                                                   "Show a backtrace.  An optional argument is accepted; if that argument is a number, it specifies the number of frames to display.  If that argument is 'all', full backtraces of all threads are displayed.",
                                                   "bt [<digit>|all]",
                                                   2,
                                                   0,
                                                   false));
    if (bt_regex_cmd_ap.get())
    {
        // accept but don't document "bt -c <number>" -- before bt was a regex command if you wanted to backtrace
        // three frames you would do "bt -c 3" but the intention is to have this emulate the gdb "bt" command and
        // so now "bt 3" is the preferred form, in line with gdb.
        if (bt_regex_cmd_ap->AddRegexCommand("^([[:digit:]]+)$", "thread backtrace -c %1") &&
            bt_regex_cmd_ap->AddRegexCommand("^-c ([[:digit:]]+)$", "thread backtrace -c %1") &&
            bt_regex_cmd_ap->AddRegexCommand("^all$", "thread backtrace all") &&
            bt_regex_cmd_ap->AddRegexCommand("^$", "thread backtrace"))
        {
            CommandObjectSP command_sp(bt_regex_cmd_ap.release());
            m_command_dict[command_sp->GetCommandName ()] = command_sp;
        }
    }

    std::unique_ptr<CommandObjectRegexCommand>
    list_regex_cmd_ap(new CommandObjectRegexCommand (*this,
                                                     "_regexp-list",
                                                     "Implements the GDB 'list' command in all of its forms except FILE:FUNCTION and maps them to the appropriate 'source list' commands.",
                                                     "_regexp-list [<line>]\n_regexp-list [<file>:<line>]\n_regexp-list [<file>:<line>]",
                                                     2,
                                                     CommandCompletions::eSourceFileCompletion,
                                                     false));
    if (list_regex_cmd_ap.get())
    {
        if (list_regex_cmd_ap->AddRegexCommand("^([0-9]+)[[:space:]]*$", "source list --line %1") &&
            list_regex_cmd_ap->AddRegexCommand("^(.*[^[:space:]])[[:space:]]*:[[:space:]]*([[:digit:]]+)[[:space:]]*$", "source list --file '%1' --line %2") &&
            list_regex_cmd_ap->AddRegexCommand("^\\*?(0x[[:xdigit:]]+)[[:space:]]*$", "source list --address %1") &&
            list_regex_cmd_ap->AddRegexCommand("^-[[:space:]]*$", "source list --reverse") &&
            list_regex_cmd_ap->AddRegexCommand("^-([[:digit:]]+)[[:space:]]*$", "source list --reverse --count %1") &&
            list_regex_cmd_ap->AddRegexCommand("^([^.]+)\\.([^.]+)$", "source list --file \"%1.%2\"") &&
            list_regex_cmd_ap->AddRegexCommand("^(.+)$", "source list --name \"%1\"") &&
            list_regex_cmd_ap->AddRegexCommand("^$", "source list"))
        {
            CommandObjectSP list_regex_cmd_sp(list_regex_cmd_ap.release());
            m_command_dict[list_regex_cmd_sp->GetCommandName ()] = list_regex_cmd_sp;
        }
    }

    std::unique_ptr<CommandObjectRegexCommand>
    env_regex_cmd_ap(new CommandObjectRegexCommand (*this,
                                                    "_regexp-env",
                                                    "Implements a shortcut to viewing and setting environment variables.",
                                                    "_regexp-env\n_regexp-env FOO=BAR",
                                                    2,
                                                    0,
                                                    false));
    if (env_regex_cmd_ap.get())
    {
        if (env_regex_cmd_ap->AddRegexCommand("^$", "settings show target.env-vars") &&
            env_regex_cmd_ap->AddRegexCommand("^([A-Za-z_][A-Za-z_0-9]*=.*)$", "settings set target.env-vars %1"))
        {
            CommandObjectSP env_regex_cmd_sp(env_regex_cmd_ap.release());
            m_command_dict[env_regex_cmd_sp->GetCommandName ()] = env_regex_cmd_sp;
        }
    }

    std::unique_ptr<CommandObjectRegexCommand>
    jump_regex_cmd_ap(new CommandObjectRegexCommand (*this,
                                                    "_regexp-jump",
                                                    "Sets the program counter to a new address.",
                                                    "_regexp-jump [<line>]\n"
                                                    "_regexp-jump [<+-lineoffset>]\n"
                                                    "_regexp-jump [<file>:<line>]\n"
                                                    "_regexp-jump [*<addr>]\n",
                                                     2,
                                                     0,
                                                     false));
    if (jump_regex_cmd_ap.get())
    {
        if (jump_regex_cmd_ap->AddRegexCommand("^\\*(.*)$", "thread jump --addr %1") &&
            jump_regex_cmd_ap->AddRegexCommand("^([0-9]+)$", "thread jump --line %1") &&
            jump_regex_cmd_ap->AddRegexCommand("^([^:]+):([0-9]+)$", "thread jump --file %1 --line %2") &&
            jump_regex_cmd_ap->AddRegexCommand("^([+\\-][0-9]+)$", "thread jump --by %1"))
        {
            CommandObjectSP jump_regex_cmd_sp(jump_regex_cmd_ap.release());
            m_command_dict[jump_regex_cmd_sp->GetCommandName ()] = jump_regex_cmd_sp;
        }
    }

}

int
CommandInterpreter::GetCommandNamesMatchingPartialString (const char *cmd_str, bool include_aliases,
                                                          StringList &matches)
{
    AddNamesMatchingPartialString (m_command_dict, cmd_str, matches);

    if (include_aliases)
    {
        AddNamesMatchingPartialString (m_alias_dict, cmd_str, matches);
    }

    return matches.GetSize();
}

CommandObjectSP
CommandInterpreter::GetCommandSP (const char *cmd_cstr, bool include_aliases, bool exact, StringList *matches)
{
    CommandObject::CommandMap::iterator pos;
    CommandObjectSP command_sp;

    std::string cmd(cmd_cstr);

    if (HasCommands())
    {
        pos = m_command_dict.find(cmd);
        if (pos != m_command_dict.end())
            command_sp = pos->second;
    }

    if (include_aliases && HasAliases())
    {
        auto alias_pos = m_alias_dict.find(cmd);
        if (alias_pos != m_alias_dict.end())
            command_sp = alias_pos->second;
    }

    if (HasUserCommands())
    {
        pos = m_user_dict.find(cmd);
        if (pos != m_user_dict.end())
            command_sp = pos->second;
    }

    if (!exact && !command_sp)
    {
        // We will only get into here if we didn't find any exact matches.
        
        CommandObjectSP user_match_sp, alias_match_sp, real_match_sp;

        StringList local_matches;
        if (matches == nullptr)
            matches = &local_matches;

        unsigned int num_cmd_matches = 0;
        unsigned int num_alias_matches = 0;
        unsigned int num_user_matches = 0;
        
        // Look through the command dictionaries one by one, and if we get only one match from any of
        // them in toto, then return that, otherwise return an empty CommandObjectSP and the list of matches.
        
        if (HasCommands())
        {
            num_cmd_matches = AddNamesMatchingPartialString (m_command_dict, cmd_cstr, *matches);
        }

        if (num_cmd_matches == 1)
        {
            cmd.assign(matches->GetStringAtIndex(0));
            pos = m_command_dict.find(cmd);
            if (pos != m_command_dict.end())
                real_match_sp = pos->second;
        }

        if (include_aliases && HasAliases())
        {
            num_alias_matches = AddNamesMatchingPartialString (m_alias_dict, cmd_cstr, *matches);

        }

        if (num_alias_matches == 1)
        {
            cmd.assign(matches->GetStringAtIndex (num_cmd_matches));
            auto alias_pos = m_alias_dict.find(cmd);
            if (alias_pos != m_alias_dict.end())
                alias_match_sp = alias_pos->second;
        }

        if (HasUserCommands())
        {
            num_user_matches = AddNamesMatchingPartialString (m_user_dict, cmd_cstr, *matches);
        }

        if (num_user_matches == 1)
        {
            cmd.assign (matches->GetStringAtIndex (num_cmd_matches + num_alias_matches));

            pos = m_user_dict.find (cmd);
            if (pos != m_user_dict.end())
                user_match_sp = pos->second;
        }
        
        // If we got exactly one match, return that, otherwise return the match list.
        
        if (num_user_matches + num_cmd_matches + num_alias_matches == 1)
        {
            if (num_cmd_matches)
                return real_match_sp;
            else if (num_alias_matches)
                return alias_match_sp;
            else
                return user_match_sp;
        }
    }
    else if (matches && command_sp)
    {
        matches->AppendString (cmd_cstr);
    }


    return command_sp;
}

bool
CommandInterpreter::AddCommand (const char *name, const lldb::CommandObjectSP &cmd_sp, bool can_replace)
{
    if (cmd_sp.get())
        assert((this == &cmd_sp->GetCommandInterpreter()) && "tried to add a CommandObject from a different interpreter");

    if (name && name[0])
    {
        std::string name_sstr(name);
        bool found = (m_command_dict.find (name_sstr) != m_command_dict.end());
        if (found && !can_replace)
            return false;
        if (found && m_command_dict[name_sstr]->IsRemovable() == false)
            return false;
        m_command_dict[name_sstr] = cmd_sp;
        return true;
    }
    return false;
}

bool
CommandInterpreter::AddUserCommand (std::string name, 
                                    const lldb::CommandObjectSP &cmd_sp,
                                    bool can_replace)
{
    if (cmd_sp.get())
        assert((this == &cmd_sp->GetCommandInterpreter()) && "tried to add a CommandObject from a different interpreter");

    if (!name.empty())
    {
        const char* name_cstr = name.c_str();
        
        // do not allow replacement of internal commands
        if (CommandExists(name_cstr))
        {
            if (can_replace == false)
                return false;
            if (m_command_dict[name]->IsRemovable() == false)
                return false;
        }
        
        if (UserCommandExists(name_cstr))
        {
            if (can_replace == false)
                return false;
            if (m_user_dict[name]->IsRemovable() == false)
                return false;
        }
        
        m_user_dict[name] = cmd_sp;
        return true;
    }
    return false;
}

CommandObjectSP
CommandInterpreter::GetCommandSPExact (const char *cmd_cstr, bool include_aliases)
{
    Args cmd_words (cmd_cstr); // Break up the command string into words, in case it's a multi-word command.
    CommandObjectSP ret_val;   // Possibly empty return value.
    
    if (cmd_cstr == nullptr)
        return ret_val;
    
    if (cmd_words.GetArgumentCount() == 1)
        return GetCommandSP(cmd_cstr, include_aliases, true, nullptr);
    else
    {
        // We have a multi-word command (seemingly), so we need to do more work.
        // First, get the cmd_obj_sp for the first word in the command.
        CommandObjectSP cmd_obj_sp = GetCommandSP (cmd_words.GetArgumentAtIndex (0), include_aliases, true, nullptr);
        if (cmd_obj_sp.get() != nullptr)
        {
            // Loop through the rest of the words in the command (everything passed in was supposed to be part of a 
            // command name), and find the appropriate sub-command SP for each command word....
            size_t end = cmd_words.GetArgumentCount();
            for (size_t j= 1; j < end; ++j)
            {
                if (cmd_obj_sp->IsMultiwordObject())
                {
                    cmd_obj_sp = cmd_obj_sp->GetSubcommandSP (cmd_words.GetArgumentAtIndex (j));
                    if (cmd_obj_sp.get() == nullptr)
                        // The sub-command name was invalid.  Fail and return the empty 'ret_val'.
                        return ret_val;
                }
                else
                    // We have more words in the command name, but we don't have a multiword object. Fail and return 
                    // empty 'ret_val'.
                    return ret_val;
            }
            // We successfully looped through all the command words and got valid command objects for them.  Assign the 
            // last object retrieved to 'ret_val'.
            ret_val = cmd_obj_sp;
        }
    }
    return ret_val;
}

CommandObject *
CommandInterpreter::GetCommandObjectExact (const char *cmd_cstr, bool include_aliases)
{
    return GetCommandSPExact (cmd_cstr, include_aliases).get();
}

CommandObject *
CommandInterpreter::GetCommandObject (const char *cmd_cstr, StringList *matches)
{
    CommandObject *command_obj = GetCommandSP (cmd_cstr, false, true, matches).get();

    // If we didn't find an exact match to the command string in the commands, look in
    // the aliases.
    
    if (command_obj)
        return command_obj;

    command_obj = GetCommandSP (cmd_cstr, true, true, matches).get();

    if (command_obj)
        return command_obj;
    
    // If there wasn't an exact match then look for an inexact one in just the commands
    command_obj = GetCommandSP(cmd_cstr, false, false, nullptr).get();

    // Finally, if there wasn't an inexact match among the commands, look for an inexact
    // match in both the commands and aliases.
    
    if (command_obj)
    {
        if (matches)
            matches->AppendString(command_obj->GetCommandName());
        return command_obj;
    }
    
    return GetCommandSP(cmd_cstr, true, false, matches).get();
}

bool
CommandInterpreter::CommandExists (const char *cmd)
{
    return m_command_dict.find(cmd) != m_command_dict.end();
}

bool
CommandInterpreter::GetAliasFullName (const char *cmd, std::string &full_name)
{
    bool exact_match  = (m_alias_dict.find(cmd) != m_alias_dict.end());
    if (exact_match)
    {
        full_name.assign(cmd);
        return exact_match;
    }
    else
    {
        StringList matches;
        size_t num_alias_matches;
        num_alias_matches = AddNamesMatchingPartialString (m_alias_dict, cmd, matches);
        if (num_alias_matches == 1)
        {
            // Make sure this isn't shadowing a command in the regular command space:
            StringList regular_matches;
            const bool include_aliases = false;
            const bool exact = false;
            CommandObjectSP cmd_obj_sp(GetCommandSP (cmd, include_aliases, exact, &regular_matches));
            if (cmd_obj_sp || regular_matches.GetSize() > 0)
                return false;
            else
            {
                full_name.assign (matches.GetStringAtIndex(0));
                return true;
            }
        }
        else
            return false;
    }
}

bool
CommandInterpreter::AliasExists (const char *cmd)
{
    return m_alias_dict.find(cmd) != m_alias_dict.end();
}

bool
CommandInterpreter::UserCommandExists (const char *cmd)
{
    return m_user_dict.find(cmd) != m_user_dict.end();
}

CommandAlias*
CommandInterpreter::AddAlias (const char *alias_name,
                              lldb::CommandObjectSP& command_obj_sp,
                              const char *args_string)
{
    if (command_obj_sp.get())
        assert((this == &command_obj_sp->GetCommandInterpreter()) && "tried to add a CommandObject from a different interpreter");
    
    std::unique_ptr<CommandAlias> command_alias_up(new CommandAlias(*this,
                                                                    command_obj_sp,
                                                                    args_string,
                                                                    alias_name));
    
    if (command_alias_up && command_alias_up->IsValid())
    {
        m_alias_dict[alias_name] = CommandObjectSP(command_alias_up.get());
        return command_alias_up.release();
    }
    
    return nullptr;
}

bool
CommandInterpreter::RemoveAlias (const char *alias_name)
{
    auto pos = m_alias_dict.find(alias_name);
    if (pos != m_alias_dict.end())
    {
        m_alias_dict.erase(pos);
        return true;
    }
    return false;
}

bool
CommandInterpreter::RemoveCommand (const char *cmd)
{
    auto pos = m_command_dict.find(cmd);
    if (pos != m_command_dict.end())
    {
        if (pos->second->IsRemovable())
        {
            // Only regular expression objects or python commands are removable
            m_command_dict.erase(pos);
            return true;
        }
    }
    return false;
}
bool
CommandInterpreter::RemoveUser (const char *alias_name)
{
    CommandObject::CommandMap::iterator pos = m_user_dict.find(alias_name);
    if (pos != m_user_dict.end())
    {
        m_user_dict.erase(pos);
        return true;
    }
    return false;
}

void
CommandInterpreter::GetHelp (CommandReturnObject &result,
                             uint32_t cmd_types)
{
    const char * help_prologue = GetDebugger().GetIOHandlerHelpPrologue();
    if (help_prologue != NULL)
    {
        OutputFormattedHelpText(result.GetOutputStream(), NULL, help_prologue);
    }

    CommandObject::CommandMap::const_iterator pos;
    size_t max_len = FindLongestCommandWord (m_command_dict);
    
    if ( (cmd_types & eCommandTypesBuiltin) == eCommandTypesBuiltin )
    {
        result.AppendMessage("Debugger commands:");
        result.AppendMessage("");

        for (pos = m_command_dict.begin(); pos != m_command_dict.end(); ++pos)
        {
            if (!(cmd_types & eCommandTypesHidden) && (pos->first.compare(0, 1, "_") == 0))
                continue;

            OutputFormattedHelpText (result.GetOutputStream(), pos->first.c_str(), "--", pos->second->GetHelp(),
                                     max_len);
        }
        result.AppendMessage("");

    }

    if (!m_alias_dict.empty() && ( (cmd_types & eCommandTypesAliases) == eCommandTypesAliases ))
    {
        result.AppendMessageWithFormat("Current command abbreviations "
                                       "(type '%shelp command alias' for more info):\n",
                                       GetCommandPrefix());
        result.AppendMessage("");
        max_len = FindLongestCommandWord (m_alias_dict);

        for (auto alias_pos = m_alias_dict.begin(); alias_pos != m_alias_dict.end(); ++alias_pos)
        {
            OutputFormattedHelpText (result.GetOutputStream(), alias_pos->first.c_str(), "--", alias_pos->second->GetHelp(),
                                     max_len);
        }
        result.AppendMessage("");
    }

    if (!m_user_dict.empty() && ( (cmd_types & eCommandTypesUserDef) == eCommandTypesUserDef ))
    {
        result.AppendMessage ("Current user-defined commands:");
        result.AppendMessage("");
        max_len = FindLongestCommandWord (m_user_dict);
        for (pos = m_user_dict.begin(); pos != m_user_dict.end(); ++pos)
        {
            OutputFormattedHelpText (result.GetOutputStream(), pos->first.c_str(), "--", pos->second->GetHelp(),
                                     max_len);
        }
        result.AppendMessage("");
    }

    result.AppendMessageWithFormat("For more information on any command, type '%shelp <command-name>'.\n",
                                   GetCommandPrefix());
}

CommandObject *
CommandInterpreter::GetCommandObjectForCommand (std::string &command_string)
{
    // This function finds the final, lowest-level, alias-resolved command object whose 'Execute' function will
    // eventually be invoked by the given command line.
    
    CommandObject *cmd_obj = nullptr;
    size_t start = command_string.find_first_not_of (k_white_space);
    size_t end = 0;
    bool done = false;
    while (!done)
    {
        if (start != std::string::npos)
        {
            // Get the next word from command_string.
            end = command_string.find_first_of (k_white_space, start);
            if (end == std::string::npos)
                end = command_string.size();
            std::string cmd_word = command_string.substr (start, end - start);
            
            if (cmd_obj == nullptr)
                // Since cmd_obj is NULL we are on our first time through this loop. Check to see if cmd_word is a valid 
                // command or alias.
                cmd_obj = GetCommandObject (cmd_word.c_str());
            else if (cmd_obj->IsMultiwordObject ())
            {
                // Our current object is a multi-word object; see if the cmd_word is a valid sub-command for our object.
                CommandObject *sub_cmd_obj = cmd_obj->GetSubcommandObject (cmd_word.c_str());
                if (sub_cmd_obj)
                    cmd_obj = sub_cmd_obj;
                else // cmd_word was not a valid sub-command word, so we are done
                    done = true;
            }
            else  
                // We have a cmd_obj and it is not a multi-word object, so we are done.
                done = true;

            // If we didn't find a valid command object, or our command object is not a multi-word object, or
            // we are at the end of the command_string, then we are done.  Otherwise, find the start of the
            // next word.
            
            if (!cmd_obj || !cmd_obj->IsMultiwordObject() || end >= command_string.size())
                done = true;
            else
                start = command_string.find_first_not_of (k_white_space, end);
        }
        else
            // Unable to find any more words.
            done = true;
    }
    
    if (end == command_string.size())
        command_string.clear();
    else
        command_string = command_string.substr(end);
    
    return cmd_obj;
}

static const char *k_valid_command_chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_";
static void
StripLeadingSpaces (std::string &s)
{
    if (!s.empty())
    {
        size_t pos = s.find_first_not_of (k_white_space);
        if (pos == std::string::npos)
            s.clear();
        else if (pos == 0)
            return;
        s.erase (0, pos);
    }
}

static size_t
FindArgumentTerminator (const std::string &s)
{
    const size_t s_len = s.size();
    size_t offset = 0;
    while (offset < s_len)
    {
        size_t pos = s.find ("--", offset);
        if (pos == std::string::npos)
            break;
        if (pos > 0)
        {
            if (isspace(s[pos-1]))
            {
                // Check if the string ends "\s--" (where \s is a space character)
                // or if we have "\s--\s".
                if ((pos + 2 >= s_len) || isspace(s[pos+2]))
                {
                    return pos;
                }
            }
        }
        offset = pos + 2;
    }
    return std::string::npos;
}

static bool
ExtractCommand (std::string &command_string, std::string &command, std::string &suffix, char &quote_char)
{
    command.clear();
    suffix.clear();
    StripLeadingSpaces (command_string);

    bool result = false;
    quote_char = '\0';
    
    if (!command_string.empty())
    {
        const char first_char = command_string[0];
        if (first_char == '\'' || first_char == '"')
        {
            quote_char = first_char;
            const size_t end_quote_pos = command_string.find (quote_char, 1);
            if (end_quote_pos == std::string::npos)
            {
                command.swap (command_string);
                command_string.erase ();
            }
            else
            {
                command.assign (command_string, 1, end_quote_pos - 1);
                if (end_quote_pos + 1 < command_string.size())
                    command_string.erase (0, command_string.find_first_not_of (k_white_space, end_quote_pos + 1));
                else
                    command_string.erase ();
            }
        }
        else
        {
            const size_t first_space_pos = command_string.find_first_of (k_white_space);
            if (first_space_pos == std::string::npos)
            {
                command.swap (command_string);
                command_string.erase();
            }
            else
            {
                command.assign (command_string, 0, first_space_pos);
                command_string.erase(0, command_string.find_first_not_of (k_white_space, first_space_pos));
            }
        }
        result = true;
    }
    
    
    if (!command.empty())
    {
        // actual commands can't start with '-' or '_'
        if (command[0] != '-' && command[0] != '_')
        {
            size_t pos = command.find_first_not_of(k_valid_command_chars);
            if (pos > 0 && pos != std::string::npos)
            {
                suffix.assign (command.begin() + pos, command.end());
                command.erase (pos);
            }
        }
    }

    return result;
}

CommandObject *
CommandInterpreter::BuildAliasResult (const char *alias_name, 
                                      std::string &raw_input_string, 
                                      std::string &alias_result,
                                      CommandReturnObject &result)
{
    CommandObject *alias_cmd_obj = nullptr;
    Args cmd_args (raw_input_string);
    alias_cmd_obj = GetCommandObject (alias_name);
    StreamString result_str;
    
    if (alias_cmd_obj && alias_cmd_obj->IsAlias())
    {
        std::pair<CommandObjectSP, OptionArgVectorSP> desugared = ((CommandAlias*)alias_cmd_obj)->Desugar();
        OptionArgVectorSP option_arg_vector_sp =  desugared.second;
        alias_cmd_obj = desugared.first.get();
        std::string alias_name_str = alias_name;
        if ((cmd_args.GetArgumentCount() == 0)
            || (alias_name_str.compare (cmd_args.GetArgumentAtIndex(0)) != 0))
            cmd_args.Unshift (alias_name);
            
        result_str.Printf ("%s", alias_cmd_obj->GetCommandName ());

        if (option_arg_vector_sp.get())
        {
            OptionArgVector *option_arg_vector = option_arg_vector_sp.get();

            for (size_t i = 0; i < option_arg_vector->size(); ++i)
            {
                OptionArgPair option_pair = (*option_arg_vector)[i];
                OptionArgValue value_pair = option_pair.second;
                int value_type = value_pair.first;
                std::string option = option_pair.first;
                std::string value = value_pair.second;
                if (option.compare ("<argument>") == 0)
                    result_str.Printf (" %s", value.c_str());
                else
                {
                    result_str.Printf (" %s", option.c_str());
                    if (value_type != OptionParser::eNoArgument)
                    {
                        if (value_type != OptionParser::eOptionalArgument)
                            result_str.Printf (" ");
                        int index = GetOptionArgumentPosition (value.c_str());
                        if (index == 0)
                            result_str.Printf ("%s", value.c_str());
                        else if (static_cast<size_t>(index) >= cmd_args.GetArgumentCount())
                        {
                            
                            result.AppendErrorWithFormat
                            ("Not enough arguments provided; you need at least %d arguments to use this alias.\n",
                             index);
                            result.SetStatus (eReturnStatusFailed);
                            return nullptr;
                        }
                        else
                        {
                            size_t strpos = raw_input_string.find (cmd_args.GetArgumentAtIndex (index));
                            if (strpos != std::string::npos)
                                raw_input_string = raw_input_string.erase (strpos, 
                                                                          strlen (cmd_args.GetArgumentAtIndex (index)));
                            result_str.Printf ("%s", cmd_args.GetArgumentAtIndex (index));
                        }
                    }
                }
            }
        }
        
        alias_result = result_str.GetData();
    }
    return alias_cmd_obj;
}

Error
CommandInterpreter::PreprocessCommand (std::string &command)
{
    // The command preprocessor needs to do things to the command 
    // line before any parsing of arguments or anything else is done.
    // The only current stuff that gets preprocessed is anything enclosed
    // in backtick ('`') characters is evaluated as an expression and
    // the result of the expression must be a scalar that can be substituted
    // into the command. An example would be:
    // (lldb) memory read `$rsp + 20`
    Error error; // Error for any expressions that might not evaluate
    size_t start_backtick;
    size_t pos = 0;
    while ((start_backtick = command.find ('`', pos)) != std::string::npos)
    {
        if (start_backtick > 0 && command[start_backtick-1] == '\\')
        {
            // The backtick was preceded by a '\' character, remove the slash
            // and don't treat the backtick as the start of an expression
            command.erase(start_backtick-1, 1);
            // No need to add one to start_backtick since we just deleted a char
            pos = start_backtick; 
        }
        else
        {
            const size_t expr_content_start = start_backtick + 1;
            const size_t end_backtick = command.find ('`', expr_content_start);
            if (end_backtick == std::string::npos)
                return error;
            else if (end_backtick == expr_content_start)
            {
                // Empty expression (two backticks in a row)
                command.erase (start_backtick, 2);
            }
            else
            {
                std::string expr_str (command, expr_content_start, end_backtick - expr_content_start);
                
                ExecutionContext exe_ctx(GetExecutionContext());
                Target *target = exe_ctx.GetTargetPtr();
                // Get a dummy target to allow for calculator mode while processing backticks.
                // This also helps break the infinite loop caused when target is null.
                if (!target)
                    target = m_debugger.GetDummyTarget();
                if (target)
                {
                    ValueObjectSP expr_result_valobj_sp;
                    
                    EvaluateExpressionOptions options;
                    options.SetCoerceToId(false);
                    options.SetUnwindOnError(true);
                    options.SetIgnoreBreakpoints(true);
                    options.SetKeepInMemory(false);
                    options.SetTryAllThreads(true);
                    options.SetTimeoutUsec(0);
                    
                    ExpressionResults expr_result = target->EvaluateExpression (expr_str.c_str(), 
                                                                                exe_ctx.GetFramePtr(),
                                                                                expr_result_valobj_sp,
                                                                                options);
                    
                    if (expr_result == eExpressionCompleted)
                    {
                        Scalar scalar;
                        if (expr_result_valobj_sp)
                            expr_result_valobj_sp = expr_result_valobj_sp->GetQualifiedRepresentationIfAvailable(expr_result_valobj_sp->GetDynamicValueType(), true);
                        if (expr_result_valobj_sp->ResolveValue (scalar))
                        {
                            command.erase (start_backtick, end_backtick - start_backtick + 1);
                            StreamString value_strm;
                            const bool show_type = false;
                            scalar.GetValue (&value_strm, show_type);
                            size_t value_string_size = value_strm.GetSize();
                            if (value_string_size)
                            {
                                command.insert (start_backtick, value_strm.GetData(), value_string_size);
                                pos = start_backtick + value_string_size;
                                continue;
                            }
                            else
                            {
                                error.SetErrorStringWithFormat("expression value didn't result in a scalar value for the expression '%s'", expr_str.c_str());
                            }
                        }
                        else
                        {
                            error.SetErrorStringWithFormat("expression value didn't result in a scalar value for the expression '%s'", expr_str.c_str());
                        }
                    }
                    else
                    {
                        if (expr_result_valobj_sp)
                            error = expr_result_valobj_sp->GetError();
                        if (error.Success())
                        {

                            switch (expr_result)
                            {
                                case eExpressionSetupError: 
                                    error.SetErrorStringWithFormat("expression setup error for the expression '%s'", expr_str.c_str());
                                    break;
                                case eExpressionParseError:
                                    error.SetErrorStringWithFormat ("expression parse error for the expression '%s'", expr_str.c_str());
                                    break;
                                case eExpressionResultUnavailable:
                                    error.SetErrorStringWithFormat ("expression error fetching result for the expression '%s'", expr_str.c_str());
                                    break;
                                case eExpressionCompleted:
                                    break;
                                case eExpressionDiscarded:
                                    error.SetErrorStringWithFormat("expression discarded for the expression '%s'", expr_str.c_str());
                                    break;
                                case eExpressionInterrupted:
                                    error.SetErrorStringWithFormat("expression interrupted for the expression '%s'", expr_str.c_str());
                                    break;
                                case eExpressionHitBreakpoint:
                                    error.SetErrorStringWithFormat("expression hit breakpoint for the expression '%s'", expr_str.c_str());
                                    break;
                                case eExpressionTimedOut:
                                    error.SetErrorStringWithFormat("expression timed out for the expression '%s'", expr_str.c_str());
                                    break;
                                case eExpressionStoppedForDebug:
                                    error.SetErrorStringWithFormat("expression stop at entry point for debugging for the expression '%s'", expr_str.c_str());
                                    break;
                            }
                        }
                    }
                }
            }
            if (error.Fail())
                break;
        }
    }
    return error;
}


bool
CommandInterpreter::HandleCommand (const char *command_line, 
                                   LazyBool lazy_add_to_history,
                                   CommandReturnObject &result,
                                   ExecutionContext *override_context,
                                   bool repeat_on_empty_command,
                                   bool no_context_switching)

{

    std::string command_string (command_line);
    std::string original_command_string (command_line);
    
    Log *log (lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_COMMANDS));
    Host::SetCrashDescriptionWithFormat ("HandleCommand(command = \"%s\")", command_line);
    
    // Make a scoped cleanup object that will clear the crash description string 
    // on exit of this function.
    lldb_utility::CleanUp <const char *> crash_description_cleanup(nullptr, Host::SetCrashDescription);

    if (log)
        log->Printf ("Processing command: %s", command_line);

    Timer scoped_timer (__PRETTY_FUNCTION__, "Handling command: %s.", command_line);
    
    if (!no_context_switching)
        UpdateExecutionContext (override_context);
    
    bool add_to_history;
    if (lazy_add_to_history == eLazyBoolCalculate)
        add_to_history = (m_command_source_depth == 0);
    else
        add_to_history = (lazy_add_to_history == eLazyBoolYes);
    
    bool empty_command = false;
    bool comment_command = false;
    if (command_string.empty())
        empty_command = true;
    else
    {
        const char *k_space_characters = "\t\n\v\f\r ";

        size_t non_space = command_string.find_first_not_of (k_space_characters);
        // Check for empty line or comment line (lines whose first
        // non-space character is the comment character for this interpreter)
        if (non_space == std::string::npos)
            empty_command = true;
        else if (command_string[non_space] == m_comment_char)
             comment_command = true;
        else if (command_string[non_space] == CommandHistory::g_repeat_char)
        {
            const char *history_string = m_command_history.FindString(command_string.c_str() + non_space);
            if (history_string == nullptr)
            {
                result.AppendErrorWithFormat ("Could not find entry: %s in history", command_string.c_str());
                result.SetStatus(eReturnStatusFailed);
                return false;
            }
            add_to_history = false;
            command_string = history_string;
            original_command_string = history_string;
        }
    }
    
    if (empty_command)
    {
        if (repeat_on_empty_command)
        {
            if (m_command_history.IsEmpty())
            {
                result.AppendError ("empty command");
                result.SetStatus(eReturnStatusFailed);
                return false;
            }
            else
            {
                command_line = m_repeat_command.c_str();
                command_string = command_line;
                original_command_string = command_line;
                if (m_repeat_command.empty())
                {
                    result.AppendErrorWithFormat("No auto repeat.\n");
                    result.SetStatus (eReturnStatusFailed);
                    return false;
                }
            }
            add_to_history = false;
        }
        else
        {
            result.SetStatus (eReturnStatusSuccessFinishNoResult);
            return true;
        }
    }
    else if (comment_command)
    {
        result.SetStatus (eReturnStatusSuccessFinishNoResult);
        return true;
    }
    
    
    Error error (PreprocessCommand (command_string));
    
    if (error.Fail())
    {
        result.AppendError (error.AsCString());
        result.SetStatus(eReturnStatusFailed);
        return false;
    }

    // Phase 1.
    
    // Before we do ANY kind of argument processing, we need to figure out what
    // the real/final command object is for the specified command.  This gets
    // complicated by the fact that the user could have specified an alias, and,
    // in translating the alias, there may also be command options and/or even
    // data (including raw text strings) that need to be found and inserted into
    // the command line as part of the translation.  So this first step is plain
    // look-up and replacement, resulting in:
    //    1. the command object whose Execute method will actually be called
    //    2. a revised command string, with all substitutions and replacements
    //       taken care of
    // From 1 above, we can determine whether the Execute function wants raw
    // input or not.

    CommandObject *cmd_obj = ResolveCommandImpl(command_string, result);

    // Although the user may have abbreviated the command, the command_string now
    // has the command expanded to the full name.  For example, if the input
    // was "br s -n main", command_string is now "breakpoint set -n main".

    if (log)
    {
        log->Printf("HandleCommand, cmd_obj : '%s'", cmd_obj ? cmd_obj->GetCommandName() : "<not found>");
        log->Printf("HandleCommand, (revised) command_string: '%s'", command_string.c_str());
        const bool wants_raw_input = (cmd_obj != NULL) ? cmd_obj->WantsRawCommandString() : false;
        log->Printf("HandleCommand, wants_raw_input:'%s'", wants_raw_input ? "True" : "False");
    }

    // Phase 2.
    // Take care of things like setting up the history command & calling the appropriate Execute method on the
    // CommandObject, with the appropriate arguments.
    
    if (cmd_obj != nullptr)
    {
        if (add_to_history)
        {
            Args command_args (command_string);
            const char *repeat_command = cmd_obj->GetRepeatCommand(command_args, 0);
            if (repeat_command != nullptr)
                m_repeat_command.assign(repeat_command);
            else
                m_repeat_command.assign(original_command_string.c_str());
            
            m_command_history.AppendString (original_command_string);
        }
        
        std::string remainder;
        const std::size_t actual_cmd_name_len = strlen (cmd_obj->GetCommandName());
        if (actual_cmd_name_len < command_string.length()) 
            remainder = command_string.substr (actual_cmd_name_len);
        
        // Remove any initial spaces
        size_t pos = remainder.find_first_not_of (k_white_space);
        if (pos != 0 && pos != std::string::npos)
            remainder.erase(0, pos);

        if (log)
            log->Printf ("HandleCommand, command line after removing command name(s): '%s'", remainder.c_str());
    
        cmd_obj->Execute (remainder.c_str(), result);
    }
    else
    {
        // We didn't find the first command object, so complete the first argument.
        Args command_args (command_string);
        StringList matches;
        int num_matches;
        int cursor_index = 0;
        int cursor_char_position = strlen (command_args.GetArgumentAtIndex(0));
        bool word_complete;
        num_matches = HandleCompletionMatches (command_args, 
                                               cursor_index,
                                               cursor_char_position,
                                               0, 
                                               -1, 
                                               word_complete,
                                               matches);
        
        if (num_matches > 0)
        {
            std::string error_msg;
            error_msg.assign ("ambiguous command '");
            error_msg.append(command_args.GetArgumentAtIndex(0));
            error_msg.append ("'.");
            
            error_msg.append (" Possible completions:");
            for (int i = 0; i < num_matches; i++)
            {
                error_msg.append ("\n\t");
                error_msg.append (matches.GetStringAtIndex (i));
            }
            error_msg.append ("\n");
            result.AppendRawError (error_msg.c_str());
        }
        else
            result.AppendErrorWithFormat ("Unrecognized command '%s'.\n", command_args.GetArgumentAtIndex (0));
        
        result.SetStatus (eReturnStatusFailed);
    }
    
    if (log)
      log->Printf ("HandleCommand, command %s", (result.Succeeded() ? "succeeded" : "did not succeed"));

    return result.Succeeded();
}

int
CommandInterpreter::HandleCompletionMatches (Args &parsed_line,
                                             int &cursor_index,
                                             int &cursor_char_position,
                                             int match_start_point,
                                             int max_return_elements,
                                             bool &word_complete,
                                             StringList &matches)
{
    int num_command_matches = 0;
    bool look_for_subcommand = false;
    
    // For any of the command completions a unique match will be a complete word.
    word_complete = true;

    if (cursor_index == -1)
    {
        // We got nothing on the command line, so return the list of commands
        bool include_aliases = true;
        num_command_matches = GetCommandNamesMatchingPartialString ("", include_aliases, matches);
    }
    else if (cursor_index == 0)
    {
        // The cursor is in the first argument, so just do a lookup in the dictionary.
        CommandObject *cmd_obj = GetCommandObject (parsed_line.GetArgumentAtIndex(0), &matches);
        num_command_matches = matches.GetSize();

        if (num_command_matches == 1
            && cmd_obj && cmd_obj->IsMultiwordObject()
            && matches.GetStringAtIndex(0) != nullptr
            && strcmp (parsed_line.GetArgumentAtIndex(0), matches.GetStringAtIndex(0)) == 0)
        {
            if (parsed_line.GetArgumentCount() == 1)
            {
                word_complete = true;
            }
            else
            {
                look_for_subcommand = true;
                num_command_matches = 0;
                matches.DeleteStringAtIndex(0);
                parsed_line.AppendArgument ("");
                cursor_index++;
                cursor_char_position = 0;
            }
        }
    }

    if (cursor_index > 0 || look_for_subcommand)
    {
        // We are completing further on into a commands arguments, so find the command and tell it
        // to complete the command.
        // First see if there is a matching initial command:
        CommandObject *command_object = GetCommandObject (parsed_line.GetArgumentAtIndex(0));
        if (command_object == nullptr)
        {
            return 0;
        }
        else
        {
            parsed_line.Shift();
            cursor_index--;
            num_command_matches = command_object->HandleCompletion (parsed_line, 
                                                                    cursor_index, 
                                                                    cursor_char_position,
                                                                    match_start_point, 
                                                                    max_return_elements,
                                                                    word_complete, 
                                                                    matches);
        }
    }

    return num_command_matches;

}

int
CommandInterpreter::HandleCompletion (const char *current_line,
                                      const char *cursor,
                                      const char *last_char,
                                      int match_start_point,
                                      int max_return_elements,
                                      StringList &matches)
{
    // We parse the argument up to the cursor, so the last argument in parsed_line is
    // the one containing the cursor, and the cursor is after the last character.

    Args parsed_line(llvm::StringRef(current_line, last_char - current_line));
    Args partial_parsed_line(llvm::StringRef(current_line, cursor - current_line));

    // Don't complete comments, and if the line we are completing is just the history repeat character, 
    // substitute the appropriate history line.
    const char *first_arg = parsed_line.GetArgumentAtIndex(0);
    if (first_arg)
    {
        if (first_arg[0] == m_comment_char)
            return 0;
        else if (first_arg[0] == CommandHistory::g_repeat_char)
        {
            const char *history_string = m_command_history.FindString (first_arg);
            if (history_string != nullptr)
            {
                matches.Clear();
                matches.InsertStringAtIndex(0, history_string);
                return -2;
            }
            else
                return 0;

        }
    }
    
    
    int num_args = partial_parsed_line.GetArgumentCount();
    int cursor_index = partial_parsed_line.GetArgumentCount() - 1;
    int cursor_char_position;

    if (cursor_index == -1)
        cursor_char_position = 0;
    else
        cursor_char_position = strlen (partial_parsed_line.GetArgumentAtIndex(cursor_index));
        
    if (cursor > current_line && cursor[-1] == ' ')
    {
        // We are just after a space.  If we are in an argument, then we will continue
        // parsing, but if we are between arguments, then we have to complete whatever the next
        // element would be.
        // We can distinguish the two cases because if we are in an argument (e.g. because the space is
        // protected by a quote) then the space will also be in the parsed argument...
        
        const char *current_elem = partial_parsed_line.GetArgumentAtIndex(cursor_index);
        if (cursor_char_position == 0 || current_elem[cursor_char_position - 1] != ' ')
        {
            parsed_line.InsertArgumentAtIndex(cursor_index + 1, "", '\0');
            cursor_index++;
            cursor_char_position = 0;
        }
    }

    int num_command_matches;

    matches.Clear();

    // Only max_return_elements == -1 is supported at present:
    assert (max_return_elements == -1);
    bool word_complete;
    num_command_matches = HandleCompletionMatches (parsed_line, 
                                                   cursor_index, 
                                                   cursor_char_position, 
                                                   match_start_point,
                                                   max_return_elements,
                                                   word_complete,
                                                   matches);

    if (num_command_matches <= 0)
        return num_command_matches;

    if (num_args == 0)
    {
        // If we got an empty string, insert nothing.
        matches.InsertStringAtIndex(0, "");
    }
    else
    {
        // Now figure out if there is a common substring, and if so put that in element 0, otherwise
        // put an empty string in element 0.
        std::string command_partial_str;
        if (cursor_index >= 0)
            command_partial_str.assign(parsed_line.GetArgumentAtIndex(cursor_index), 
                                       parsed_line.GetArgumentAtIndex(cursor_index) + cursor_char_position);

        std::string common_prefix;
        matches.LongestCommonPrefix (common_prefix);
        const size_t partial_name_len = command_partial_str.size();
        common_prefix.erase (0, partial_name_len);

        // If we matched a unique single command, add a space...
        // Only do this if the completer told us this was a complete word, however...
        if (num_command_matches == 1 && word_complete)
        {
            char quote_char = parsed_line.GetArgumentQuoteCharAtIndex(cursor_index);
            common_prefix = Args::EscapeLLDBCommandArgument(common_prefix, quote_char);
            if (quote_char != '\0')
                common_prefix.push_back(quote_char);
            common_prefix.push_back(' ');
        }
        matches.InsertStringAtIndex(0, common_prefix.c_str());
    }
    return num_command_matches;
}


CommandInterpreter::~CommandInterpreter ()
{
}

void
CommandInterpreter::UpdatePrompt (const char *new_prompt)
{
    EventSP prompt_change_event_sp (new Event(eBroadcastBitResetPrompt, new EventDataBytes (new_prompt)));;
    BroadcastEvent (prompt_change_event_sp);
    if (m_command_io_handler_sp)
        m_command_io_handler_sp->SetPrompt(new_prompt);
}


bool 
CommandInterpreter::Confirm (const char *message, bool default_answer)
{
    // Check AutoConfirm first:
    if (m_debugger.GetAutoConfirm())
        return default_answer;
    
    IOHandlerConfirm *confirm = new IOHandlerConfirm(m_debugger,
                                                     message,
                                                     default_answer);
    IOHandlerSP io_handler_sp (confirm);
    m_debugger.RunIOHandler (io_handler_sp);
    return confirm->GetResponse();
}
    
CommandAlias*
CommandInterpreter::GetAlias (const char *alias_name)
{
    OptionArgVectorSP ret_val;

    std::string alias (alias_name);

    auto pos = m_alias_dict.find(alias);
    if (pos != m_alias_dict.end())
        return (CommandAlias*)pos->second.get();
    
    return nullptr;
}

bool
CommandInterpreter::HasCommands ()
{
    return (!m_command_dict.empty());
}

bool
CommandInterpreter::HasAliases ()
{
    return (!m_alias_dict.empty());
}

bool
CommandInterpreter::HasUserCommands ()
{
    return (!m_user_dict.empty());
}

bool
CommandInterpreter::HasAliasOptions ()
{
    return HasAliases();
}

void
CommandInterpreter::BuildAliasCommandArgs (CommandObject *alias_cmd_obj,
                                           const char *alias_name,
                                           Args &cmd_args,
                                           std::string &raw_input_string,
                                           CommandReturnObject &result)
{
    OptionArgVectorSP option_arg_vector_sp = GetAlias(alias_name)->GetOptionArguments();
    
    bool wants_raw_input = alias_cmd_obj->WantsRawCommandString();

    // Make sure that the alias name is the 0th element in cmd_args
    std::string alias_name_str = alias_name;
    if (alias_name_str.compare (cmd_args.GetArgumentAtIndex(0)) != 0)
        cmd_args.Unshift (alias_name);
    
    Args new_args (alias_cmd_obj->GetCommandName());
    if (new_args.GetArgumentCount() == 2)
        new_args.Shift();
    
    if (option_arg_vector_sp.get())
    {
        if (wants_raw_input)
        {
            // We have a command that both has command options and takes raw input.  Make *sure* it has a
            // " -- " in the right place in the raw_input_string.
            size_t pos = raw_input_string.find(" -- ");
            if (pos == std::string::npos)
            {
                // None found; assume it goes at the beginning of the raw input string
                raw_input_string.insert (0, " -- ");
            }
        }

        OptionArgVector *option_arg_vector = option_arg_vector_sp.get();
        const size_t old_size = cmd_args.GetArgumentCount();
        std::vector<bool> used (old_size + 1, false);
        
        used[0] = true;

        for (size_t i = 0; i < option_arg_vector->size(); ++i)
        {
            OptionArgPair option_pair = (*option_arg_vector)[i];
            OptionArgValue value_pair = option_pair.second;
            int value_type = value_pair.first;
            std::string option = option_pair.first;
            std::string value = value_pair.second;
            if (option.compare ("<argument>") == 0)
            {
                if (!wants_raw_input
                    || (value.compare("--") != 0)) // Since we inserted this above, make sure we don't insert it twice
                    new_args.AppendArgument (value.c_str());
            }
            else
            {
                if (value_type != OptionParser::eOptionalArgument)
                    new_args.AppendArgument (option.c_str());
                if (value.compare ("<no-argument>") != 0)
                {
                    int index = GetOptionArgumentPosition (value.c_str());
                    if (index == 0)
                    {
                        // value was NOT a positional argument; must be a real value
                        if (value_type != OptionParser::eOptionalArgument)
                            new_args.AppendArgument (value.c_str());
                        else
                        {
                            char buffer[255];
                            ::snprintf (buffer, sizeof (buffer), "%s%s", option.c_str(), value.c_str());
                            new_args.AppendArgument (buffer);
                        }

                    }
                    else if (static_cast<size_t>(index) >= cmd_args.GetArgumentCount())
                    {
                        result.AppendErrorWithFormat
                                    ("Not enough arguments provided; you need at least %d arguments to use this alias.\n",
                                     index);
                        result.SetStatus (eReturnStatusFailed);
                        return;
                    }
                    else
                    {
                        // Find and remove cmd_args.GetArgumentAtIndex(i) from raw_input_string
                        size_t strpos = raw_input_string.find (cmd_args.GetArgumentAtIndex (index));
                        if (strpos != std::string::npos)
                        {
                            raw_input_string = raw_input_string.erase (strpos, strlen (cmd_args.GetArgumentAtIndex (index)));
                        }

                        if (value_type != OptionParser::eOptionalArgument)
                            new_args.AppendArgument (cmd_args.GetArgumentAtIndex (index));
                        else
                        {
                            char buffer[255];
                            ::snprintf (buffer, sizeof(buffer), "%s%s", option.c_str(), 
                                        cmd_args.GetArgumentAtIndex (index));
                            new_args.AppendArgument (buffer);
                        }
                        used[index] = true;
                    }
                }
            }
        }

        for (size_t j = 0; j < cmd_args.GetArgumentCount(); ++j)
        {
            if (!used[j] && !wants_raw_input)
                new_args.AppendArgument (cmd_args.GetArgumentAtIndex (j));
        }

        cmd_args.Clear();
        cmd_args.SetArguments (new_args.GetArgumentCount(), new_args.GetConstArgumentVector());
    }
    else
    {
        result.SetStatus (eReturnStatusSuccessFinishNoResult);
        // This alias was not created with any options; nothing further needs to be done, unless it is a command that
        // wants raw input, in which case we need to clear the rest of the data from cmd_args, since its in the raw
        // input string.
        if (wants_raw_input)
        {
            cmd_args.Clear();
            cmd_args.SetArguments (new_args.GetArgumentCount(), new_args.GetConstArgumentVector());
        }
        return;
    }

    result.SetStatus (eReturnStatusSuccessFinishNoResult);
    return;
}


int
CommandInterpreter::GetOptionArgumentPosition (const char *in_string)
{
    int position = 0;   // Any string that isn't an argument position, i.e. '%' followed by an integer, gets a position
                        // of zero.

    const char *cptr = in_string;

    // Does it start with '%'
    if (cptr[0] == '%')
    {
        ++cptr;

        // Is the rest of it entirely digits?
        if (isdigit (cptr[0]))
        {
            const char *start = cptr;
            while (isdigit (cptr[0]))
                ++cptr;

            // We've gotten to the end of the digits; are we at the end of the string?
            if (cptr[0] == '\0')
                position = atoi (start);
        }
    }

    return position;
}

void
CommandInterpreter::SourceInitFile (bool in_cwd, CommandReturnObject &result)
{
    FileSpec init_file;
    if (in_cwd)
    {
        ExecutionContext exe_ctx(GetExecutionContext());
        Target *target = exe_ctx.GetTargetPtr();
        if (target)
        {
            // In the current working directory we don't load any program specific
            // .lldbinit files, we only look for a ".lldbinit" file.
            if (m_skip_lldbinit_files)
                return;

            LoadCWDlldbinitFile should_load = target->TargetProperties::GetLoadCWDlldbinitFile ();
            if (should_load == eLoadCWDlldbinitWarn)
            {
                FileSpec dot_lldb (".lldbinit", true);
                llvm::SmallString<64> home_dir_path;
                llvm::sys::path::home_directory (home_dir_path);
                FileSpec homedir_dot_lldb (home_dir_path.c_str(), false);
                homedir_dot_lldb.AppendPathComponent (".lldbinit");
                homedir_dot_lldb.ResolvePath ();
                if (dot_lldb.Exists ()
                    && dot_lldb.GetDirectory() != homedir_dot_lldb.GetDirectory())
                {
                    result.AppendErrorWithFormat (
                            "There is a .lldbinit file in the current directory which is not being read.\n"
                            "To silence this warning without sourcing in the local .lldbinit,\n"
                            "add the following to the lldbinit file in your home directory:\n"
                            "    settings set target.load-cwd-lldbinit false\n"
                            "To allow lldb to source .lldbinit files in the current working directory,\n"
                            "set the value of this variable to true.  Only do so if you understand and\n"
                            "accept the security risk.");
                    result.SetStatus (eReturnStatusFailed);
                    return;
                }
            }
            else if (should_load == eLoadCWDlldbinitTrue)
            {
                init_file.SetFile ("./.lldbinit", true);
            }
        }
    }
    else
    {
        // If we aren't looking in the current working directory we are looking
        // in the home directory. We will first see if there is an application
        // specific ".lldbinit" file whose name is "~/.lldbinit" followed by a 
        // "-" and the name of the program. If this file doesn't exist, we fall
        // back to just the "~/.lldbinit" file. We also obey any requests to not
        // load the init files.
        llvm::SmallString<64> home_dir_path;
        llvm::sys::path::home_directory(home_dir_path);
        FileSpec profilePath(home_dir_path.c_str(), false);
        profilePath.AppendPathComponent(".lldbinit");
        std::string init_file_path = profilePath.GetPath();

        if (m_skip_app_init_files == false)
        {
            FileSpec program_file_spec(HostInfo::GetProgramFileSpec());
            const char *program_name = program_file_spec.GetFilename().AsCString();
    
            if (program_name)
            {
                char program_init_file_name[PATH_MAX];
                ::snprintf (program_init_file_name, sizeof(program_init_file_name), "%s-%s", init_file_path.c_str(), program_name);
                init_file.SetFile (program_init_file_name, true);
                if (!init_file.Exists())
                    init_file.Clear();
            }
        }
        
        if (!init_file && !m_skip_lldbinit_files)
			init_file.SetFile (init_file_path.c_str(), false);
    }

    // If the file exists, tell HandleCommand to 'source' it; this will do the actual broadcasting
    // of the commands back to any appropriate listener (see CommandObjectSource::Execute for more details).

    if (init_file.Exists())
    {
        const bool saved_batch = SetBatchCommandMode (true);
        CommandInterpreterRunOptions options;
        options.SetSilent (true);
        options.SetStopOnError (false);
        options.SetStopOnContinue (true);

        HandleCommandsFromFile (init_file,
                                nullptr,           // Execution context
                                options,
                                result);
        SetBatchCommandMode (saved_batch);
    }
    else
    {
        // nothing to be done if the file doesn't exist
        result.SetStatus(eReturnStatusSuccessFinishNoResult);
    }
}

const char *
CommandInterpreter::GetCommandPrefix()
{
    const char * prefix = GetDebugger().GetIOHandlerCommandPrefix();
    return prefix == NULL ? "" : prefix;
}

PlatformSP
CommandInterpreter::GetPlatform (bool prefer_target_platform)
{
    PlatformSP platform_sp;
    if (prefer_target_platform)
    {
        ExecutionContext exe_ctx(GetExecutionContext());
        Target *target = exe_ctx.GetTargetPtr();
        if (target)
            platform_sp = target->GetPlatform();
    }

    if (!platform_sp)
        platform_sp = m_debugger.GetPlatformList().GetSelectedPlatform();
    return platform_sp;
}

void
CommandInterpreter::HandleCommands (const StringList &commands, 
                                    ExecutionContext *override_context,
                                    CommandInterpreterRunOptions &options,
                                    CommandReturnObject &result)
{
    size_t num_lines = commands.GetSize();
    
    // If we are going to continue past a "continue" then we need to run the commands synchronously.
    // Make sure you reset this value anywhere you return from the function.
    
    bool old_async_execution = m_debugger.GetAsyncExecution();
    
    // If we've been given an execution context, set it at the start, but don't keep resetting it or we will
    // cause series of commands that change the context, then do an operation that relies on that context to fail.
    
    if (override_context != nullptr)
        UpdateExecutionContext (override_context);
            
    if (!options.GetStopOnContinue())
    {
        m_debugger.SetAsyncExecution (false);
    }

    for (size_t idx = 0; idx < num_lines; idx++)
    {
        const char *cmd = commands.GetStringAtIndex(idx);
        if (cmd[0] == '\0')
            continue;
            
        if (options.GetEchoCommands())
        {
            result.AppendMessageWithFormat ("%s %s\n", 
                                            m_debugger.GetPrompt(),
                                            cmd);
        }

        CommandReturnObject tmp_result;
        // If override_context is not NULL, pass no_context_switching = true for
        // HandleCommand() since we updated our context already.
        
        // We might call into a regex or alias command, in which case the add_to_history will get lost.  This
        // m_command_source_depth dingus is the way we turn off adding to the history in that case, so set it up here.
        if (!options.GetAddToHistory())
            m_command_source_depth++;
        bool success = HandleCommand(cmd, options.m_add_to_history, tmp_result,
                                     nullptr, /* override_context */
                                     true, /* repeat_on_empty_command */
                                     override_context != nullptr /* no_context_switching */);
        if (!options.GetAddToHistory())
            m_command_source_depth--;
        
        if (options.GetPrintResults())
        {
            if (tmp_result.Succeeded())
              result.AppendMessageWithFormat("%s", tmp_result.GetOutputData());
        }
                
        if (!success || !tmp_result.Succeeded())
        {
            const char *error_msg = tmp_result.GetErrorData();
            if (error_msg == nullptr || error_msg[0] == '\0')
                error_msg = "<unknown error>.\n";
            if (options.GetStopOnError())
            {
                result.AppendErrorWithFormat("Aborting reading of commands after command #%" PRIu64 ": '%s' failed with %s",
                                                (uint64_t)idx, cmd, error_msg);
                result.SetStatus (eReturnStatusFailed);
                m_debugger.SetAsyncExecution (old_async_execution);
                return;
            }
            else if (options.GetPrintResults())
            {
                result.AppendMessageWithFormat ("Command #%" PRIu64 " '%s' failed with %s",
                                                (uint64_t)idx + 1,
                                                cmd, 
                                                error_msg);
            }
        }
        
        if (result.GetImmediateOutputStream())
            result.GetImmediateOutputStream()->Flush();
        
        if (result.GetImmediateErrorStream())
            result.GetImmediateErrorStream()->Flush();
        
        // N.B. Can't depend on DidChangeProcessState, because the state coming into the command execution
        // could be running (for instance in Breakpoint Commands.
        // So we check the return value to see if it is has running in it.
        if ((tmp_result.GetStatus() == eReturnStatusSuccessContinuingNoResult)
                || (tmp_result.GetStatus() == eReturnStatusSuccessContinuingResult))
        {
            if (options.GetStopOnContinue())
            {
                // If we caused the target to proceed, and we're going to stop in that case, set the
                // status in our real result before returning.  This is an error if the continue was not the
                // last command in the set of commands to be run.
                if (idx != num_lines - 1)
                    result.AppendErrorWithFormat("Aborting reading of commands after command #%" PRIu64 ": '%s' continued the target.\n", 
                                                 (uint64_t)idx + 1, cmd);
                else
                    result.AppendMessageWithFormat("Command #%" PRIu64 " '%s' continued the target.\n", (uint64_t)idx + 1, cmd);
                    
                result.SetStatus(tmp_result.GetStatus());
                m_debugger.SetAsyncExecution (old_async_execution);

                return;
            }
        }

        // Also check for "stop on crash here:
        bool should_stop = false;
        if (tmp_result.GetDidChangeProcessState() && options.GetStopOnCrash())
        {
            TargetSP target_sp (m_debugger.GetTargetList().GetSelectedTarget());
            if (target_sp)
            {
                ProcessSP process_sp (target_sp->GetProcessSP());
                if (process_sp)
                {
                    for (ThreadSP thread_sp : process_sp->GetThreadList().Threads())
                    {
                        StopReason reason = thread_sp->GetStopReason();
                        if (reason == eStopReasonSignal || reason == eStopReasonException || reason == eStopReasonInstrumentation)
                        {
                            should_stop = true;
                            break;
                        }
                    }
                }
            }
            if (should_stop)
            {
                if (idx != num_lines - 1)
                    result.AppendErrorWithFormat("Aborting reading of commands after command #%" PRIu64 ": '%s' stopped with a signal or exception.\n",
                                                 (uint64_t)idx + 1, cmd);
                else
                    result.AppendMessageWithFormat("Command #%" PRIu64 " '%s' stopped with a signal or exception.\n", (uint64_t)idx + 1, cmd);
                    
                result.SetStatus(tmp_result.GetStatus());
                m_debugger.SetAsyncExecution (old_async_execution);

                return;
            }
        }
        
    }
    
    result.SetStatus (eReturnStatusSuccessFinishResult);
    m_debugger.SetAsyncExecution (old_async_execution);

    return;
}

// Make flags that we can pass into the IOHandler so our delegates can do the right thing
enum {
    eHandleCommandFlagStopOnContinue = (1u << 0),
    eHandleCommandFlagStopOnError    = (1u << 1),
    eHandleCommandFlagEchoCommand    = (1u << 2),
    eHandleCommandFlagPrintResult    = (1u << 3),
    eHandleCommandFlagStopOnCrash    = (1u << 4)
};

void
CommandInterpreter::HandleCommandsFromFile (FileSpec &cmd_file, 
                                            ExecutionContext *context, 
                                            CommandInterpreterRunOptions &options,
                                            CommandReturnObject &result)
{
    if (cmd_file.Exists())
    {
        StreamFileSP input_file_sp (new StreamFile());
        
        std::string cmd_file_path = cmd_file.GetPath();
        Error error = input_file_sp->GetFile().Open(cmd_file_path.c_str(), File::eOpenOptionRead);
        
        if (error.Success())
        {
            Debugger &debugger = GetDebugger();

            uint32_t flags = 0;

            if (options.m_stop_on_continue == eLazyBoolCalculate)
            {
                if (m_command_source_flags.empty())
                {
                    // Stop on continue by default
                    flags |= eHandleCommandFlagStopOnContinue;
                }
                else if (m_command_source_flags.back() & eHandleCommandFlagStopOnContinue)
                {
                    flags |= eHandleCommandFlagStopOnContinue;
                }
            }
            else if (options.m_stop_on_continue == eLazyBoolYes)
            {
                flags |= eHandleCommandFlagStopOnContinue;
            }

            if (options.m_stop_on_error == eLazyBoolCalculate)
            {
                if (m_command_source_flags.empty())
                {
                    if (GetStopCmdSourceOnError())
                        flags |= eHandleCommandFlagStopOnError;
                }
                else if (m_command_source_flags.back() & eHandleCommandFlagStopOnError)
                {
                    flags |= eHandleCommandFlagStopOnError;
                }
            }
            else if (options.m_stop_on_error == eLazyBoolYes)
            {
                flags |= eHandleCommandFlagStopOnError;
            }

            if (options.GetStopOnCrash())
            {
                if (m_command_source_flags.empty())
                {
                    // Echo command by default
                    flags |= eHandleCommandFlagStopOnCrash;
                }
                else if (m_command_source_flags.back() & eHandleCommandFlagStopOnCrash)
                {
                    flags |= eHandleCommandFlagStopOnCrash;
                }
            }

            if (options.m_echo_commands == eLazyBoolCalculate)
            {
                if (m_command_source_flags.empty())
                {
                    // Echo command by default
                    flags |= eHandleCommandFlagEchoCommand;
                }
                else if (m_command_source_flags.back() & eHandleCommandFlagEchoCommand)
                {
                    flags |= eHandleCommandFlagEchoCommand;
                }
            }
            else if (options.m_echo_commands == eLazyBoolYes)
            {
                flags |= eHandleCommandFlagEchoCommand;
            }

            if (options.m_print_results == eLazyBoolCalculate)
            {
                if (m_command_source_flags.empty())
                {
                    // Print output by default
                    flags |= eHandleCommandFlagPrintResult;
                }
                else if (m_command_source_flags.back() & eHandleCommandFlagPrintResult)
                {
                    flags |= eHandleCommandFlagPrintResult;
                }
            }
            else if (options.m_print_results == eLazyBoolYes)
            {
                flags |= eHandleCommandFlagPrintResult;
            }

            if (flags & eHandleCommandFlagPrintResult)
            {
                debugger.GetOutputFile()->Printf("Executing commands in '%s'.\n", cmd_file_path.c_str());
            }

            // Used for inheriting the right settings when "command source" might have
            // nested "command source" commands
            lldb::StreamFileSP empty_stream_sp;
            m_command_source_flags.push_back(flags);
            IOHandlerSP io_handler_sp (new IOHandlerEditline (debugger,
                                                              IOHandler::Type::CommandInterpreter,
                                                              input_file_sp,
                                                              empty_stream_sp, // Pass in an empty stream so we inherit the top input reader output stream
                                                              empty_stream_sp, // Pass in an empty stream so we inherit the top input reader error stream
                                                              flags,
                                                              nullptr, // Pass in NULL for "editline_name" so no history is saved, or written
                                                              debugger.GetPrompt(),
                                                              NULL,
                                                              false, // Not multi-line
                                                              debugger.GetUseColor(),
                                                              0,
                                                              *this));
            const bool old_async_execution = debugger.GetAsyncExecution();
            
            // Set synchronous execution if we are not stopping on continue
            if ((flags & eHandleCommandFlagStopOnContinue) == 0)
                debugger.SetAsyncExecution (false);

            m_command_source_depth++;
            
            debugger.RunIOHandler(io_handler_sp);
            if (!m_command_source_flags.empty())
                m_command_source_flags.pop_back();
            m_command_source_depth--;
            result.SetStatus (eReturnStatusSuccessFinishNoResult);
            debugger.SetAsyncExecution (old_async_execution);
        }
        else
        {
            result.AppendErrorWithFormat ("error: an error occurred read file '%s': %s\n", cmd_file_path.c_str(), error.AsCString());
            result.SetStatus (eReturnStatusFailed);
        }
        

    }
    else
    {
        result.AppendErrorWithFormat ("Error reading commands from file %s - file not found.\n", 
                                      cmd_file.GetFilename().AsCString("<Unknown>"));
        result.SetStatus (eReturnStatusFailed);
        return;
    }
}

ScriptInterpreter *
CommandInterpreter::GetScriptInterpreter(bool can_create)
{
    if (m_script_interpreter_sp)
        return m_script_interpreter_sp.get();

    if (!can_create)
        return nullptr;

    lldb::ScriptLanguage script_lang = GetDebugger().GetScriptLanguage();
    m_script_interpreter_sp = PluginManager::GetScriptInterpreterForLanguage(script_lang, *this);
    return m_script_interpreter_sp.get();
}

bool
CommandInterpreter::GetSynchronous ()
{
    return m_synchronous_execution;
}

void
CommandInterpreter::SetSynchronous (bool value)
{
    m_synchronous_execution  = value;
}

void
CommandInterpreter::OutputFormattedHelpText (Stream &strm,
                                             const char *prefix,
                                             const char *help_text)
{
    const uint32_t max_columns = m_debugger.GetTerminalWidth();
    if (prefix == NULL)
        prefix = "";

    size_t prefix_width = strlen(prefix);
    size_t line_width_max = max_columns - prefix_width;
    const char *help_text_end = help_text + strlen(help_text);
    const char *line_start = help_text;
    if (line_width_max < 16)
        line_width_max = help_text_end - help_text + prefix_width;

    strm.IndentMore (prefix_width);
    while (line_start < help_text_end)
    {
        // Break each line at the first newline or last space/tab before
        // the maximum number of characters that fit on a line.  Lines with no
        // natural break are left unbroken to wrap.
        const char *line_end = help_text_end;
        const char *line_scan = line_start;
        const char *line_scan_end = help_text_end;
        while (line_scan < line_scan_end)
        {
            char next = *line_scan;
            if (next == '\t' || next == ' ')
            {
                line_end = line_scan;
                line_scan_end = line_start + line_width_max;
            }
            else if (next == '\n' || next == '\0')
            {
                line_end = line_scan;
                break;
            }
            ++line_scan;
        }
        
        // Prefix the first line, indent subsequent lines to line up
        if (line_start == help_text)
            strm.Write (prefix, prefix_width);
        else
            strm.Indent();
        strm.Write (line_start, line_end - line_start);
        strm.EOL();

        // When a line breaks at whitespace consume it before continuing
        line_start = line_end;
        char next = *line_start;
        if (next == '\n')
            ++line_start;
        else while (next == ' ' || next == '\t')
            next = *(++line_start);
    }
    strm.IndentLess (prefix_width);
}

void
CommandInterpreter::OutputFormattedHelpText (Stream &strm,
                                             const char *word_text,
                                             const char *separator,
                                             const char *help_text,
                                             size_t max_word_len)
{
    StreamString prefix_stream;
    prefix_stream.Printf ("  %-*s %s ",  (int)max_word_len, word_text, separator);
    OutputFormattedHelpText (strm, prefix_stream.GetData(), help_text);
}

void
CommandInterpreter::OutputHelpText (Stream &strm,
                                    const char *word_text,
                                    const char *separator,
                                    const char *help_text,
                                    uint32_t max_word_len)
{
    int indent_size = max_word_len + strlen (separator) + 2;
    
    strm.IndentMore (indent_size);
    
    StreamString text_strm;
    text_strm.Printf ("%-*s %s %s",  max_word_len, word_text, separator, help_text);
    
    const uint32_t max_columns = m_debugger.GetTerminalWidth();
    
    size_t len = text_strm.GetSize();
    const char *text = text_strm.GetData();
        
    uint32_t chars_left = max_columns;

    for (uint32_t i = 0; i < len; i++)
    {
        if ((text[i] == ' ' && ::strchr((text+i+1), ' ') && chars_left < ::strchr((text+i+1), ' ')-(text+i)) || text[i] == '\n')
        {
            chars_left = max_columns - indent_size;
            strm.EOL();
            strm.Indent();
        }
        else
        {
            strm.PutChar(text[i]);
            chars_left--;
        }
        
    }
    
    strm.EOL();
    strm.IndentLess(indent_size);
}

void
CommandInterpreter::FindCommandsForApropos (const char *search_word,
                                            StringList &commands_found,
                                            StringList &commands_help,
                                            CommandObject::CommandMap &command_map)
{
    CommandObject::CommandMap::const_iterator pos;
    
    for (pos = command_map.begin(); pos != command_map.end(); ++pos)
    {
        const char *command_name = pos->first.c_str();
        CommandObject *cmd_obj = pos->second.get();
        
        const bool search_short_help = true;
        const bool search_long_help = false;
        const bool search_syntax = false;
        const bool search_options = false;
        if (strcasestr(command_name, search_word) ||
            cmd_obj->HelpTextContainsWord (search_word,
                                           search_short_help,
                                           search_long_help,
                                           search_syntax,
                                           search_options))
        {
            commands_found.AppendString (command_name);
            commands_help.AppendString (cmd_obj->GetHelp());
        }
        
        if (cmd_obj->IsMultiwordObject())
        {
            CommandObjectMultiword *cmd_multiword = cmd_obj->GetAsMultiwordCommand();
            FindCommandsForApropos(search_word,
                                   commands_found,
                                   commands_help,
                                   cmd_multiword->GetSubcommandDictionary());
        }
    }
}


void
CommandInterpreter::FindCommandsForApropos (const char *search_word,
                                            StringList &commands_found,
                                            StringList &commands_help,
                                            bool search_builtin_commands,
                                            bool search_user_commands,
                                            bool search_alias_commands)
{
    CommandObject::CommandMap::const_iterator pos;

    if (search_builtin_commands)
        FindCommandsForApropos(search_word, commands_found, commands_help, m_command_dict);
    
    if (search_user_commands)
        FindCommandsForApropos(search_word, commands_found, commands_help, m_user_dict);

    if (search_alias_commands)
        FindCommandsForApropos(search_word, commands_found, commands_help, m_alias_dict);
}

void
CommandInterpreter::UpdateExecutionContext (ExecutionContext *override_context)
{
    if (override_context != nullptr)
    {
        m_exe_ctx_ref = *override_context;
    }
    else
    {
        const bool adopt_selected = true;
        m_exe_ctx_ref.SetTargetPtr (m_debugger.GetSelectedTarget().get(), adopt_selected);
    }
}


size_t
CommandInterpreter::GetProcessOutput ()
{
    //  The process has stuff waiting for stderr; get it and write it out to the appropriate place.
    char stdio_buffer[1024];
    size_t len;
    size_t total_bytes = 0;
    Error error;
    TargetSP target_sp (m_debugger.GetTargetList().GetSelectedTarget());
    if (target_sp)
    {
        ProcessSP process_sp (target_sp->GetProcessSP());
        if (process_sp)
        {
            while ((len = process_sp->GetSTDOUT (stdio_buffer, sizeof (stdio_buffer), error)) > 0)
            {
                size_t bytes_written = len;
                m_debugger.GetOutputFile()->Write (stdio_buffer, bytes_written);
                total_bytes += len;
            }
            while ((len = process_sp->GetSTDERR (stdio_buffer, sizeof (stdio_buffer), error)) > 0)
            {
                size_t bytes_written = len;
                m_debugger.GetErrorFile()->Write (stdio_buffer, bytes_written);
                total_bytes += len;
            }
        }
    }
    return total_bytes;
}

void
CommandInterpreter::IOHandlerInputComplete (IOHandler &io_handler, std::string &line)
{
    const bool is_interactive = io_handler.GetIsInteractive();
    if (is_interactive == false)
    {
        // When we are not interactive, don't execute blank lines. This will happen
        // sourcing a commands file. We don't want blank lines to repeat the previous
        // command and cause any errors to occur (like redefining an alias, get an error
        // and stop parsing the commands file).
        if (line.empty())
            return;
        
        // When using a non-interactive file handle (like when sourcing commands from a file)
        // we need to echo the command out so we don't just see the command output and no
        // command...
        if (io_handler.GetFlags().Test(eHandleCommandFlagEchoCommand))
            io_handler.GetOutputStreamFile()->Printf("%s%s\n", io_handler.GetPrompt(), line.c_str());
    }

    lldb_private::CommandReturnObject result;
    HandleCommand(line.c_str(), eLazyBoolCalculate, result);
    
    // Now emit the command output text from the command we just executed
    if (io_handler.GetFlags().Test(eHandleCommandFlagPrintResult))
    {
        // Display any STDOUT/STDERR _prior_ to emitting the command result text
        GetProcessOutput ();
        
        if (!result.GetImmediateOutputStream())
        {
            const char *output = result.GetOutputData();
            if (output && output[0])
                io_handler.GetOutputStreamFile()->PutCString(output);
        }
    
        // Now emit the command error text from the command we just executed
        if (!result.GetImmediateErrorStream())
        {
            const char *error = result.GetErrorData();
            if (error && error[0])
                io_handler.GetErrorStreamFile()->PutCString(error);
        }
    }
    
    switch (result.GetStatus())
    {
        case eReturnStatusInvalid:
        case eReturnStatusSuccessFinishNoResult:
        case eReturnStatusSuccessFinishResult:
        case eReturnStatusStarted:
            break;

        case eReturnStatusSuccessContinuingNoResult:
        case eReturnStatusSuccessContinuingResult:
            if (io_handler.GetFlags().Test(eHandleCommandFlagStopOnContinue))
                io_handler.SetIsDone(true);
            break;

        case eReturnStatusFailed:
            m_num_errors++;
            if (io_handler.GetFlags().Test(eHandleCommandFlagStopOnError))
                io_handler.SetIsDone(true);
            break;
            
        case eReturnStatusQuit:
            m_quit_requested = true;
            io_handler.SetIsDone(true);
            break;
    }

    // Finally, if we're going to stop on crash, check that here:
    if (!m_quit_requested
        && result.GetDidChangeProcessState()
        && io_handler.GetFlags().Test(eHandleCommandFlagStopOnCrash))
    {
        bool should_stop = false;
        TargetSP target_sp (m_debugger.GetTargetList().GetSelectedTarget());
        if (target_sp)
        {
            ProcessSP process_sp (target_sp->GetProcessSP());
            if (process_sp)
            {
                for (ThreadSP thread_sp : process_sp->GetThreadList().Threads())
                {
                    StopReason reason = thread_sp->GetStopReason();
                    if ((reason == eStopReasonSignal
                        || reason == eStopReasonException
                        || reason == eStopReasonInstrumentation)
                        && !result.GetAbnormalStopWasExpected())
                    {
                        should_stop = true;
                        break;
                    }
                }
            }
        }
        if (should_stop)
        {
            io_handler.SetIsDone(true);
            m_stopped_for_crash = true;
        }
    }
}

bool
CommandInterpreter::IOHandlerInterrupt (IOHandler &io_handler)
{
    ExecutionContext exe_ctx (GetExecutionContext());
    Process *process = exe_ctx.GetProcessPtr();
    
    if (process)
    {
        StateType state = process->GetState();
        if (StateIsRunningState(state))
        {
            process->Halt();
            return true; // Don't do any updating when we are running
        }
    }

    ScriptInterpreter *script_interpreter = GetScriptInterpreter (false);
    if (script_interpreter)
    {
        if (script_interpreter->Interrupt())
            return true;
    }
    return false;
}

void
CommandInterpreter::GetLLDBCommandsFromIOHandler (const char *prompt,
                                                  IOHandlerDelegate &delegate,
                                                  bool asynchronously,
                                                  void *baton)
{
    Debugger &debugger = GetDebugger();
    IOHandlerSP io_handler_sp (new IOHandlerEditline (debugger,
                                                      IOHandler::Type::CommandList,
                                                      "lldb",       // Name of input reader for history
                                                      prompt,       // Prompt
                                                      NULL,         // Continuation prompt
                                                      true,         // Get multiple lines
                                                      debugger.GetUseColor(),
                                                      0,            // Don't show line numbers
                                                      delegate));   // IOHandlerDelegate
    
    if (io_handler_sp)
    {
        io_handler_sp->SetUserData (baton);
        if (asynchronously)
            debugger.PushIOHandler(io_handler_sp);
        else
            debugger.RunIOHandler(io_handler_sp);
    }
    
}


void
CommandInterpreter::GetPythonCommandsFromIOHandler (const char *prompt,
                                                    IOHandlerDelegate &delegate,
                                                    bool asynchronously,
                                                    void *baton)
{
    Debugger &debugger = GetDebugger();
    IOHandlerSP io_handler_sp (new IOHandlerEditline (debugger,
                                                      IOHandler::Type::PythonCode,
                                                      "lldb-python",    // Name of input reader for history
                                                      prompt,           // Prompt
                                                      NULL,             // Continuation prompt
                                                      true,             // Get multiple lines
                                                      debugger.GetUseColor(),
                                                      0,                // Don't show line numbers
                                                      delegate));       // IOHandlerDelegate
    
    if (io_handler_sp)
    {
        io_handler_sp->SetUserData (baton);
        if (asynchronously)
            debugger.PushIOHandler(io_handler_sp);
        else
            debugger.RunIOHandler(io_handler_sp);
    }

}

bool
CommandInterpreter::IsActive ()
{
    return m_debugger.IsTopIOHandler (m_command_io_handler_sp);
}

lldb::IOHandlerSP
CommandInterpreter::GetIOHandler(bool force_create, CommandInterpreterRunOptions *options)
{
    // Always re-create the IOHandlerEditline in case the input
    // changed. The old instance might have had a non-interactive
    // input and now it does or vice versa.
    if (force_create || !m_command_io_handler_sp)
    {
        // Always re-create the IOHandlerEditline in case the input
        // changed. The old instance might have had a non-interactive
        // input and now it does or vice versa.
        uint32_t flags = 0;
        
        if (options)
        {
            if (options->m_stop_on_continue == eLazyBoolYes)
                flags |= eHandleCommandFlagStopOnContinue;
            if (options->m_stop_on_error == eLazyBoolYes)
                flags |= eHandleCommandFlagStopOnError;
            if (options->m_stop_on_crash == eLazyBoolYes)
                flags |= eHandleCommandFlagStopOnCrash;
            if (options->m_echo_commands != eLazyBoolNo)
                flags |= eHandleCommandFlagEchoCommand;
            if (options->m_print_results != eLazyBoolNo)
                flags |= eHandleCommandFlagPrintResult;
        }
        else
        {
            flags = eHandleCommandFlagEchoCommand | eHandleCommandFlagPrintResult;
        }
        
        m_command_io_handler_sp.reset(new IOHandlerEditline (m_debugger,
                                                             IOHandler::Type::CommandInterpreter,
                                                             m_debugger.GetInputFile(),
                                                             m_debugger.GetOutputFile(),
                                                             m_debugger.GetErrorFile(),
                                                             flags,
                                                             "lldb",
                                                             m_debugger.GetPrompt(),
                                                             NULL,                      // Continuation prompt
                                                             false,                     // Don't enable multiple line input, just single line commands
                                                             m_debugger.GetUseColor(),
                                                             0,            // Don't show line numbers
                                                             *this));
    }
    return m_command_io_handler_sp;
}

void
CommandInterpreter::RunCommandInterpreter(bool auto_handle_events,
                                          bool spawn_thread,
                                          CommandInterpreterRunOptions &options)
{
    // Always re-create the command interpreter when we run it in case
    // any file handles have changed.
    bool force_create = true;
    m_debugger.PushIOHandler(GetIOHandler(force_create, &options));
    m_stopped_for_crash = false;
    
    if (auto_handle_events)
        m_debugger.StartEventHandlerThread();
    
    if (spawn_thread)
    {
        m_debugger.StartIOHandlerThread();
    }
    else
    {
        m_debugger.ExecuteIOHandlers();
        
        if (auto_handle_events)
            m_debugger.StopEventHandlerThread();
    }
    
}

CommandObject *
CommandInterpreter::ResolveCommandImpl(std::string &command_line, CommandReturnObject &result)
{
    std::string scratch_command(command_line);  // working copy so we don't modify command_line unless we succeed
    CommandObject *cmd_obj = nullptr;
    StreamString revised_command_line;
    bool wants_raw_input = false;
    size_t actual_cmd_name_len = 0;
    std::string next_word;
    StringList matches;
    bool done = false;
    while (!done)
    {
        char quote_char = '\0';
        std::string suffix;
        ExtractCommand(scratch_command, next_word, suffix, quote_char);
        if (cmd_obj == nullptr)
        {
            std::string full_name;
            if (GetAliasFullName(next_word.c_str(), full_name))
            {
                std::string alias_result;
                cmd_obj = BuildAliasResult(full_name.c_str(), scratch_command, alias_result, result);
                revised_command_line.Printf("%s", alias_result.c_str());
                if (cmd_obj)
                {
                    wants_raw_input = cmd_obj->WantsRawCommandString();
                    actual_cmd_name_len = strlen(cmd_obj->GetCommandName());
                }
            }
            else
            {
                cmd_obj = GetCommandObject(next_word.c_str(), &matches);
                if (cmd_obj)
                {
                    actual_cmd_name_len += strlen(cmd_obj->GetCommandName());
                    revised_command_line.Printf("%s", cmd_obj->GetCommandName());
                    wants_raw_input = cmd_obj->WantsRawCommandString();
                }
                else
                {
                    revised_command_line.Printf ("%s", next_word.c_str());
                }
            }
        }
        else
        {
            if (cmd_obj->IsMultiwordObject ())
            {
                CommandObject *sub_cmd_obj = cmd_obj->GetSubcommandObject(next_word.c_str());
                if (sub_cmd_obj)
                {
                    // The subcommand's name includes the parent command's name,
                    // so restart rather than append to the revised_command_line.
                    actual_cmd_name_len = strlen(sub_cmd_obj->GetCommandName()) + 1;
                    revised_command_line.Clear();
                    revised_command_line.Printf("%s", sub_cmd_obj->GetCommandName());
                    cmd_obj = sub_cmd_obj;
                    wants_raw_input = cmd_obj->WantsRawCommandString();
                }
                else
                {
                    if (quote_char)
                        revised_command_line.Printf(" %c%s%s%c", quote_char, next_word.c_str(), suffix.c_str(), quote_char);
                    else
                        revised_command_line.Printf(" %s%s", next_word.c_str(), suffix.c_str());
                    done = true;
                }
            }
            else
            {
                if (quote_char)
                    revised_command_line.Printf(" %c%s%s%c", quote_char, next_word.c_str(), suffix.c_str(), quote_char);
                else
                    revised_command_line.Printf(" %s%s", next_word.c_str(), suffix.c_str());
                done = true;
            }
        }

        if (cmd_obj == nullptr)
        {
            const size_t num_matches = matches.GetSize();
            if (matches.GetSize() > 1) {
                StreamString error_msg;
                error_msg.Printf("Ambiguous command '%s'. Possible matches:\n", next_word.c_str());

                for (uint32_t i = 0; i < num_matches; ++i) {
                    error_msg.Printf("\t%s\n", matches.GetStringAtIndex(i));
                }
                result.AppendRawError(error_msg.GetString().c_str());
            } else {
                // We didn't have only one match, otherwise we wouldn't get here.
                assert(num_matches == 0);
                result.AppendErrorWithFormat("'%s' is not a valid command.\n", next_word.c_str());
            }
            result.SetStatus(eReturnStatusFailed);
            return nullptr;
        }

        if (cmd_obj->IsMultiwordObject())
        {
            if (!suffix.empty())
            {
                result.AppendErrorWithFormat("command '%s' did not recognize '%s%s%s' as valid (subcommand might be invalid).\n",
                                             cmd_obj->GetCommandName(),
                                             next_word.empty() ? "" : next_word.c_str(),
                                             next_word.empty() ? " -- " : " ",
                                             suffix.c_str());
                result.SetStatus(eReturnStatusFailed);
                return nullptr;
            }
        }
        else
        {
            // If we found a normal command, we are done
            done = true;
            if (!suffix.empty())
            {
                switch (suffix[0])
                {
                case '/':
                    // GDB format suffixes
                    {
                        Options *command_options = cmd_obj->GetOptions();
                        if (command_options && command_options->SupportsLongOption("gdb-format"))
                        {
                            std::string gdb_format_option("--gdb-format=");
                            gdb_format_option += (suffix.c_str() + 1);

                            bool inserted = false;
                            std::string &cmd = revised_command_line.GetString();
                            size_t arg_terminator_idx = FindArgumentTerminator(cmd);
                            if (arg_terminator_idx != std::string::npos)
                            {
                                // Insert the gdb format option before the "--" that terminates options
                                gdb_format_option.append(1,' ');
                                cmd.insert(arg_terminator_idx, gdb_format_option);
                                inserted = true;
                            }

                            if (!inserted)
                                revised_command_line.Printf(" %s", gdb_format_option.c_str());

                            if (wants_raw_input && FindArgumentTerminator(cmd) == std::string::npos)
                                revised_command_line.PutCString(" --");
                        }
                        else
                        {
                            result.AppendErrorWithFormat("the '%s' command doesn't support the --gdb-format option\n",
                                                         cmd_obj->GetCommandName());
                            result.SetStatus(eReturnStatusFailed);
                            return nullptr;
                        }
                    }
                    break;

                default:
                    result.AppendErrorWithFormat("unknown command shorthand suffix: '%s'\n",
                                                 suffix.c_str());
                    result.SetStatus(eReturnStatusFailed);
                    return nullptr;
                }
            }
        }
        if (scratch_command.empty())
            done = true;
    }

    if (!scratch_command.empty())
        revised_command_line.Printf(" %s", scratch_command.c_str());

    if (cmd_obj != NULL)
        command_line = revised_command_line.GetData();

    return cmd_obj;
}
